Auto merge of #67505 - Centril:rollup-7win7ty, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #67148 ( Refactor type & bounds parsing thoroughly)
 - #67410 (Reenable static linking of libstdc++ on windows-gnu)
 - #67439 (Cleanup `lower_pattern_unadjusted` & Improve slice pat typeck)
 - #67480 (Require issue = "none" over issue = "0" in unstable attributes)
 - #67500 (Tweak non_shorthand_field_patterns' suggestion)
 - #67504 (Warn against relying on ?Sized being last)

Failed merges:

r? @ghost

31 files changed, 87 insertions, 87 deletions

diff --git a/src/libcore/array/mod.rs b/src/libcore/array/mod.rs
index 38d248d701d..fd80000b6fb 100644
--- a/src/libcore/array/mod.rs
+++ b/src/libcore/array/mod.rs
@@ -74,7 +74,7 @@ impl TryFromSliceError {
     #[unstable(feature = "array_error_internals",
            reason = "available through Error trait and this method should not \
                      be exposed publicly",
-           issue = "0")]
+           issue = "none")]
     #[inline]
     #[doc(hidden)]
     pub fn __description(&self) -> &str {
@@ -388,14 +388,14 @@ where
 #[rustc_on_unimplemented(
     message="arrays only have std trait implementations for lengths 0..=32",
 )]
-#[unstable(feature = "const_generic_impls_guard", issue = "0",
+#[unstable(feature = "const_generic_impls_guard", issue = "none",
     reason = "will never be stable, just a temporary step until const generics are stable")]
 pub trait LengthAtMost32 {}
 
 macro_rules! array_impls {
     ($($N:literal)+) => {
         $(
-            #[unstable(feature = "const_generic_impls_guard", issue = "0")]
+            #[unstable(feature = "const_generic_impls_guard", issue = "none")]
             impl<T> LengthAtMost32 for [T; $N] {}
         )+
     }
diff --git a/src/libcore/char/convert.rs b/src/libcore/char/convert.rs
index dd21c72e745..315020bac58 100644
--- a/src/libcore/char/convert.rs
+++ b/src/libcore/char/convert.rs
@@ -169,7 +169,7 @@ impl ParseCharError {
     #[unstable(
         feature = "char_error_internals",
         reason = "this method should not be available publicly",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     pub fn __description(&self) -> &str {
diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index 18f808638de..9a412e57294 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -150,7 +150,7 @@ pub macro Clone($item:item) {
 #[unstable(
     feature = "derive_clone_copy",
     reason = "deriving hack, should not be public",
-    issue = "0"
+    issue = "none"
 )]
 pub struct AssertParamIsClone<T: Clone + ?Sized> {
     _field: crate::marker::PhantomData<T>,
@@ -160,7 +160,7 @@ pub struct AssertParamIsClone<T: Clone + ?Sized> {
 #[unstable(
     feature = "derive_clone_copy",
     reason = "deriving hack, should not be public",
-    issue = "0"
+    issue = "none"
 )]
 pub struct AssertParamIsCopy<T: Copy + ?Sized> {
     _field: crate::marker::PhantomData<T>,
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 4aa52a7a390..a0e72fb66b0 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -288,7 +288,7 @@ pub macro Eq($item:item) { /* compiler built-in */ }
 #[allow(missing_debug_implementations)]
 #[unstable(feature = "derive_eq",
            reason = "deriving hack, should not be public",
-           issue = "0")]
+           issue = "none")]
 pub struct AssertParamIsEq<T: Eq + ?Sized> { _field: crate::marker::PhantomData<T> }
 
 /// An `Ordering` is the result of a comparison between two values.
diff --git a/src/libcore/ffi.rs b/src/libcore/ffi.rs
index 74ec24939a3..6277da4f123 100644
--- a/src/libcore/ffi.rs
+++ b/src/libcore/ffi.rs
@@ -38,14 +38,14 @@ pub enum c_void {
     #[unstable(
         feature = "c_void_variant",
         reason = "temporary implementation detail",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     __variant1,
     #[unstable(
         feature = "c_void_variant",
         reason = "temporary implementation detail",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     __variant2,
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 793c1f124ed..6c8d1626b09 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -35,7 +35,7 @@ pub enum Alignment {
 #[stable(feature = "debug_builders", since = "1.2.0")]
 pub use self::builders::{DebugList, DebugMap, DebugSet, DebugStruct, DebugTuple};
 
-#[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+#[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
 #[doc(hidden)]
 pub mod rt {
     pub mod v1;
@@ -259,7 +259,7 @@ struct Void {
 /// types, and then this struct is used to canonicalize arguments to one type.
 #[derive(Copy, Clone)]
 #[allow(missing_debug_implementations)]
-#[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+#[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
 #[doc(hidden)]
 pub struct ArgumentV1<'a> {
     value: &'a Void,
@@ -273,13 +273,13 @@ impl<'a> ArgumentV1<'a> {
     }
 
     #[doc(hidden)]
-    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
     pub fn new<'b, T>(x: &'b T, f: fn(&T, &mut Formatter<'_>) -> Result) -> ArgumentV1<'b> {
         unsafe { ArgumentV1 { formatter: mem::transmute(f), value: mem::transmute(x) } }
     }
 
     #[doc(hidden)]
-    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
     pub fn from_usize(x: &usize) -> ArgumentV1<'_> {
         ArgumentV1::new(x, ArgumentV1::show_usize)
     }
@@ -309,7 +309,7 @@ impl<'a> Arguments<'a> {
     /// Arguments structure.
     #[doc(hidden)]
     #[inline]
-    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
     pub fn new_v1(pieces: &'a [&'a str], args: &'a [ArgumentV1<'a>]) -> Arguments<'a> {
         Arguments { pieces, fmt: None, args }
     }
@@ -322,7 +322,7 @@ impl<'a> Arguments<'a> {
     /// unsafety, but will ignore invalid .
     #[doc(hidden)]
     #[inline]
-    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
     pub fn new_v1_formatted(
         pieces: &'a [&'a str],
         args: &'a [ArgumentV1<'a>],
@@ -337,7 +337,7 @@ impl<'a> Arguments<'a> {
     /// when using `format!`. Note: this is neither the lower nor upper bound.
     #[doc(hidden)]
     #[inline]
-    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "0")]
+    #[unstable(feature = "fmt_internals", reason = "internal to format_args!", issue = "none")]
     pub fn estimated_capacity(&self) -> usize {
         let pieces_length: usize = self.pieces.iter().map(|x| x.len()).sum();
 
diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index 0db8d86ebbf..2a7fa58dd30 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -90,7 +90,7 @@ use crate::marker;
 #[allow(deprecated)]
 pub use self::sip::SipHasher;
 
-#[unstable(feature = "hashmap_internals", issue = "0")]
+#[unstable(feature = "hashmap_internals", issue = "none")]
 #[allow(deprecated)]
 #[doc(hidden)]
 pub use self::sip::SipHasher13;
diff --git a/src/libcore/hash/sip.rs b/src/libcore/hash/sip.rs
index 0aa3b97ebcf..7ebe01e26dc 100644
--- a/src/libcore/hash/sip.rs
+++ b/src/libcore/hash/sip.rs
@@ -15,7 +15,7 @@ use crate::ptr;
 /// (e.g., `collections::HashMap` uses it by default).
 ///
 /// See: <https://131002.net/siphash>
-#[unstable(feature = "hashmap_internals", issue = "0")]
+#[unstable(feature = "hashmap_internals", issue = "none")]
 #[rustc_deprecated(
     since = "1.13.0",
     reason = "use `std::collections::hash_map::DefaultHasher` instead"
@@ -29,7 +29,7 @@ pub struct SipHasher13 {
 /// An implementation of SipHash 2-4.
 ///
 /// See: <https://131002.net/siphash/>
-#[unstable(feature = "hashmap_internals", issue = "0")]
+#[unstable(feature = "hashmap_internals", issue = "none")]
 #[rustc_deprecated(
     since = "1.13.0",
     reason = "use `std::collections::hash_map::DefaultHasher` instead"
@@ -172,7 +172,7 @@ impl SipHasher {
 impl SipHasher13 {
     /// Creates a new `SipHasher13` with the two initial keys set to 0.
     #[inline]
-    #[unstable(feature = "hashmap_internals", issue = "0")]
+    #[unstable(feature = "hashmap_internals", issue = "none")]
     #[rustc_deprecated(
         since = "1.13.0",
         reason = "use `std::collections::hash_map::DefaultHasher` instead"
@@ -183,7 +183,7 @@ impl SipHasher13 {
 
     /// Creates a `SipHasher13` that is keyed off the provided keys.
     #[inline]
-    #[unstable(feature = "hashmap_internals", issue = "0")]
+    #[unstable(feature = "hashmap_internals", issue = "none")]
     #[rustc_deprecated(
         since = "1.13.0",
         reason = "use `std::collections::hash_map::DefaultHasher` instead"
@@ -264,7 +264,7 @@ impl super::Hasher for SipHasher {
     }
 }
 
-#[unstable(feature = "hashmap_internals", issue = "0")]
+#[unstable(feature = "hashmap_internals", issue = "none")]
 impl super::Hasher for SipHasher13 {
     #[inline]
     fn write(&mut self, msg: &[u8]) {
diff --git a/src/libcore/internal_macros.rs b/src/libcore/internal_macros.rs
index 3acf2ec837d..4ea7dfc0735 100644
--- a/src/libcore/internal_macros.rs
+++ b/src/libcore/internal_macros.rs
@@ -77,7 +77,7 @@ macro_rules! forward_ref_op_assign {
 }
 
 /// Create a zero-size type similar to a closure type, but named.
-#[unstable(feature = "std_internals", issue = "0")]
+#[unstable(feature = "std_internals", issue = "none")]
 macro_rules! impl_fn_for_zst {
     ($(
         $( #[$attr: meta] )*
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index b02acce2d00..e73d125c13f 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -33,7 +33,7 @@
             reason = "intrinsics are unlikely to ever be stabilized, instead \
                       they should be used through stabilized interfaces \
                       in the rest of the standard library",
-            issue = "0")]
+            issue = "none")]
 #![allow(missing_docs)]
 
 use crate::mem;
@@ -709,7 +709,7 @@ extern "rust-intrinsic" {
                reason = "intrinsics are unlikely to ever be stabilized, instead \
                          they should be used through stabilized interfaces \
                          in the rest of the standard library",
-               issue = "0")]
+               issue = "none")]
     #[rustc_deprecated(reason = "superseded by MaybeUninit, removal planned",
                        since = "1.38.0")]
     pub fn init<T>() -> T;
@@ -725,7 +725,7 @@ extern "rust-intrinsic" {
                reason = "intrinsics are unlikely to ever be stabilized, instead \
                          they should be used through stabilized interfaces \
                          in the rest of the standard library",
-               issue = "0")]
+               issue = "none")]
     #[rustc_deprecated(reason = "superseded by MaybeUninit, removal planned",
                        since = "1.38.0")]
     pub fn uninit<T>() -> T;
diff --git a/src/libcore/macros/mod.rs b/src/libcore/macros/mod.rs
index dd06da7a6d2..6c7ec2cbfe3 100644
--- a/src/libcore/macros/mod.rs
+++ b/src/libcore/macros/mod.rs
@@ -799,7 +799,7 @@ pub(crate) mod builtin {
     /// Same as `format_args`, but adds a newline in the end.
     #[unstable(
         feature = "format_args_nl",
-        issue = "0",
+        issue = "none",
         reason = "`format_args_nl` is only for internal \
                   language use and is subject to change"
     )]
diff --git a/src/libcore/mem/maybe_uninit.rs b/src/libcore/mem/maybe_uninit.rs
index 7f80f61aaf9..de3b837fb68 100644
--- a/src/libcore/mem/maybe_uninit.rs
+++ b/src/libcore/mem/maybe_uninit.rs
@@ -301,7 +301,7 @@ impl<T> MaybeUninit<T> {
     /// let mut buf: [MaybeUninit<u8>; 32] = MaybeUninit::uninit_array();
     /// let data = read(&mut buf);
     /// ```
-    #[unstable(feature = "maybe_uninit_uninit_array", issue = "0")]
+    #[unstable(feature = "maybe_uninit_uninit_array", issue = "none")]
     #[inline(always)]
     pub fn uninit_array<const LEN: usize>() -> [Self; LEN] {
         unsafe {
@@ -310,7 +310,7 @@ impl<T> MaybeUninit<T> {
     }
 
     /// A promotable constant, equivalent to `uninit()`.
-    #[unstable(feature = "internal_uninit_const", issue = "0",
+    #[unstable(feature = "internal_uninit_const", issue = "none",
         reason = "hack to work around promotability")]
     pub const UNINIT: Self = Self::uninit();
 
@@ -749,7 +749,7 @@ impl<T> MaybeUninit<T> {
     /// It is up to the caller to guarantee that the `MaybeUninit<T>` elements
     /// really are in an initialized state.
     /// Calling this when the content is not yet fully initialized causes undefined behavior.
-    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "0")]
+    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "none")]
     #[inline(always)]
     pub unsafe fn slice_get_ref(slice: &[Self]) -> &[T] {
         &*(slice as *const [Self] as *const [T])
@@ -762,7 +762,7 @@ impl<T> MaybeUninit<T> {
     /// It is up to the caller to guarantee that the `MaybeUninit<T>` elements
     /// really are in an initialized state.
     /// Calling this when the content is not yet fully initialized causes undefined behavior.
-    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "0")]
+    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "none")]
     #[inline(always)]
     pub unsafe fn slice_get_mut(slice: &mut [Self]) -> &mut [T] {
         &mut *(slice as *mut [Self] as *mut [T])
diff --git a/src/libcore/mem/mod.rs b/src/libcore/mem/mod.rs
index 4e8ba8131f7..db5d2650331 100644
--- a/src/libcore/mem/mod.rs
+++ b/src/libcore/mem/mod.rs
@@ -121,7 +121,7 @@ pub fn forget<T>(t: T) {
 ///
 /// [`forget`]: fn.forget.html
 #[inline]
-#[unstable(feature = "forget_unsized", issue = "0")]
+#[unstable(feature = "forget_unsized", issue = "none")]
 pub fn forget_unsized<T: ?Sized>(t: T) {
     // SAFETY: the forget intrinsic could be safe, but there's no point in making it safe since
     // we'll be implementing this function soon via `ManuallyDrop`
diff --git a/src/libcore/num/bignum.rs b/src/libcore/num/bignum.rs
index b8ddd5322a1..39cc381b64c 100644
--- a/src/libcore/num/bignum.rs
+++ b/src/libcore/num/bignum.rs
@@ -15,7 +15,7 @@
 #![unstable(
     feature = "core_private_bignum",
     reason = "internal routines only exposed for testing",
-    issue = "0"
+    issue = "none"
 )]
 #![macro_use]
 
diff --git a/src/libcore/num/dec2flt/mod.rs b/src/libcore/num/dec2flt/mod.rs
index 6fe9af8cbd8..c83c6b0eccb 100644
--- a/src/libcore/num/dec2flt/mod.rs
+++ b/src/libcore/num/dec2flt/mod.rs
@@ -81,7 +81,7 @@
 #![unstable(
     feature = "dec2flt",
     reason = "internal routines only exposed for testing",
-    issue = "0"
+    issue = "none"
 )]
 
 use crate::fmt;
@@ -187,7 +187,7 @@ impl ParseFloatError {
         feature = "int_error_internals",
         reason = "available through Error trait and this method should \
                   not be exposed publicly",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     pub fn __description(&self) -> &str {
diff --git a/src/libcore/num/diy_float.rs b/src/libcore/num/diy_float.rs
index 0e601d45a21..0a609417dcf 100644
--- a/src/libcore/num/diy_float.rs
+++ b/src/libcore/num/diy_float.rs
@@ -6,7 +6,7 @@
 #![unstable(
     feature = "core_private_diy_float",
     reason = "internal routines only exposed for testing",
-    issue = "0"
+    issue = "none"
 )]
 
 /// A custom 64-bit floating point type, representing `f * 2^e`.
diff --git a/src/libcore/num/flt2dec/mod.rs b/src/libcore/num/flt2dec/mod.rs
index 63df5613453..9e760c13c0c 100644
--- a/src/libcore/num/flt2dec/mod.rs
+++ b/src/libcore/num/flt2dec/mod.rs
@@ -119,7 +119,7 @@ functions.
 #![unstable(
     feature = "flt2dec",
     reason = "internal routines only exposed for testing",
-    issue = "0"
+    issue = "none"
 )]
 
 pub use self::decoder::{decode, DecodableFloat, Decoded, FullDecoded};
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 6c864f74b1f..8a32479b2ff 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -4769,7 +4769,7 @@ impl TryFromIntError {
         feature = "int_error_internals",
         reason = "available through Error trait and this method should \
                   not be exposed publicly",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     pub fn __description(&self) -> &str {
@@ -4968,7 +4968,7 @@ impl ParseIntError {
         feature = "int_error_internals",
         reason = "available through Error trait and this method should \
                   not be exposed publicly",
-        issue = "0"
+        issue = "none"
     )]
     #[doc(hidden)]
     pub fn __description(&self) -> &str {
diff --git a/src/libcore/ops/deref.rs b/src/libcore/ops/deref.rs
index f521355a907..68244fdb381 100644
--- a/src/libcore/ops/deref.rs
+++ b/src/libcore/ops/deref.rs
@@ -178,14 +178,14 @@ impl<T: ?Sized> DerefMut for &mut T {
 /// `arbitrary_self_types` feature. This is implemented by stdlib pointer types like `Box<T>`,
 /// `Rc<T>`, `&T`, and `Pin<P>`.
 #[lang = "receiver"]
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 #[doc(hidden)]
 pub trait Receiver {
     // Empty.
 }
 
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized> Receiver for &T {}
 
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 impl<T: ?Sized> Receiver for &mut T {}
diff --git a/src/libcore/ops/mod.rs b/src/libcore/ops/mod.rs
index 80ab906961e..77b92b6ccbd 100644
--- a/src/libcore/ops/mod.rs
+++ b/src/libcore/ops/mod.rs
@@ -168,7 +168,7 @@ pub use self::bit::{BitAndAssign, BitOrAssign, BitXorAssign, ShlAssign, ShrAssig
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::deref::{Deref, DerefMut};
 
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 pub use self::deref::Receiver;
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -195,5 +195,5 @@ pub use self::generator::{Generator, GeneratorState};
 #[unstable(feature = "coerce_unsized", issue = "27732")]
 pub use self::unsize::CoerceUnsized;
 
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 pub use self::unsize::DispatchFromDyn;
diff --git a/src/libcore/ops/unsize.rs b/src/libcore/ops/unsize.rs
index 80fb5642a6a..95a4393592b 100644
--- a/src/libcore/ops/unsize.rs
+++ b/src/libcore/ops/unsize.rs
@@ -81,21 +81,21 @@ impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
 ///     T: Unsize<U>,
 /// {}
 /// ```
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 #[lang = "dispatch_from_dyn"]
 pub trait DispatchFromDyn<T> {
     // Empty.
 }
 
 // &T -> &U
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<&'a U> for &'a T {}
 // &mut T -> &mut U
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<&'a mut U> for &'a mut T {}
 // *const T -> *const U
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<*const U> for *const T {}
 // *mut T -> *mut U
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<*mut U> for *mut T {}
diff --git a/src/libcore/panic.rs b/src/libcore/panic.rs
index c9a1c4b0049..a90b025c093 100644
--- a/src/libcore/panic.rs
+++ b/src/libcore/panic.rs
@@ -40,7 +40,7 @@ impl<'a> PanicInfo<'a> {
     #[unstable(feature = "panic_internals",
                reason = "internal details of the implementation of the `panic!` \
                          and related macros",
-               issue = "0")]
+               issue = "none")]
     #[doc(hidden)]
     #[inline]
     pub fn internal_constructor(
@@ -58,7 +58,7 @@ impl<'a> PanicInfo<'a> {
     #[unstable(feature = "panic_internals",
                reason = "internal details of the implementation of the `panic!` \
                          and related macros",
-               issue = "0")]
+               issue = "none")]
     #[doc(hidden)]
     #[inline]
     pub fn set_payload(&mut self, info: &'a (dyn Any + Send)) {
@@ -235,7 +235,7 @@ impl<'a> Location<'a> {
     #![unstable(feature = "panic_internals",
                 reason = "internal details of the implementation of the `panic!` \
                           and related macros",
-                issue = "0")]
+                issue = "none")]
     #[doc(hidden)]
     pub const fn internal_constructor(file: &'a str, line: u32, col: u32) -> Self {
         Location { file, line, col }
@@ -318,7 +318,7 @@ impl fmt::Display for Location<'_> {
 /// An internal trait used by libstd to pass data from libstd to `panic_unwind`
 /// and other panic runtimes. Not intended to be stabilized any time soon, do
 /// not use.
-#[unstable(feature = "std_internals", issue = "0")]
+#[unstable(feature = "std_internals", issue = "none")]
 #[doc(hidden)]
 pub unsafe trait BoxMeUp {
     /// Take full ownership of the contents.
diff --git a/src/libcore/panicking.rs b/src/libcore/panicking.rs
index 4857b114595..7ebb72e3ce7 100644
--- a/src/libcore/panicking.rs
+++ b/src/libcore/panicking.rs
@@ -26,7 +26,7 @@
     feature = "core_panic",
     reason = "internal details of the implementation of the `panic!` \
               and related macros",
-    issue = "0"
+    issue = "none"
 )]
 
 use crate::fmt;
diff --git a/src/libcore/pin.rs b/src/libcore/pin.rs
index 6a0c5bbebc1..aca6fb20138 100644
--- a/src/libcore/pin.rs
+++ b/src/libcore/pin.rs
@@ -786,7 +786,7 @@ impl<P: DerefMut<Target: Unpin>> DerefMut for Pin<P> {
     }
 }
 
-#[unstable(feature = "receiver_trait", issue = "0")]
+#[unstable(feature = "receiver_trait", issue = "none")]
 impl<P: Receiver> Receiver for Pin<P> {}
 
 #[stable(feature = "pin", since = "1.33.0")]
diff --git a/src/libcore/ptr/mod.rs b/src/libcore/ptr/mod.rs
index 924563fc44f..d42b673ff65 100644
--- a/src/libcore/ptr/mod.rs
+++ b/src/libcore/ptr/mod.rs
@@ -89,7 +89,7 @@ mod non_null;
 pub use non_null::NonNull;
 
 mod unique;
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 pub use unique::Unique;
 
 mod const_ptr;
diff --git a/src/libcore/ptr/non_null.rs b/src/libcore/ptr/non_null.rs
index 6946fd2413e..626e58d4930 100644
--- a/src/libcore/ptr/non_null.rs
+++ b/src/libcore/ptr/non_null.rs
@@ -149,7 +149,7 @@ impl<T: ?Sized> Copy for NonNull<T> {}
 #[unstable(feature = "coerce_unsized", issue = "27732")]
 impl<T: ?Sized, U: ?Sized> CoerceUnsized<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
 
-#[unstable(feature = "dispatch_from_dyn", issue = "0")]
+#[unstable(feature = "dispatch_from_dyn", issue = "none")]
 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NonNull<U>> for NonNull<T> where T: Unsize<U> {}
 
 #[stable(feature = "nonnull", since = "1.25.0")]
@@ -201,7 +201,7 @@ impl<T: ?Sized> hash::Hash for NonNull<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> From<Unique<T>> for NonNull<T> {
     #[inline]
     fn from(unique: Unique<T>) -> Self {
diff --git a/src/libcore/ptr/unique.rs b/src/libcore/ptr/unique.rs
index 546b7c9d777..87b56d951c6 100644
--- a/src/libcore/ptr/unique.rs
+++ b/src/libcore/ptr/unique.rs
@@ -29,7 +29,7 @@ use crate::ptr::NonNull;
 /// for any type which upholds Unique's aliasing requirements.
 #[unstable(
     feature = "ptr_internals",
-    issue = "0",
+    issue = "none",
     reason = "use `NonNull` instead and consider `PhantomData<T>` \
               (if you also use `#[may_dangle]`), `Send`, and/or `Sync`"
 )]
@@ -50,17 +50,17 @@ pub struct Unique<T: ?Sized> {
 /// reference is unaliased. Note that this aliasing invariant is
 /// unenforced by the type system; the abstraction using the
 /// `Unique` must enforce it.
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 unsafe impl<T: Send + ?Sized> Send for Unique<T> {}
 
 /// `Unique` pointers are `Sync` if `T` is `Sync` because the data they
 /// reference is unaliased. Note that this aliasing invariant is
 /// unenforced by the type system; the abstraction using the
 /// `Unique` must enforce it.
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 unsafe impl<T: Sync + ?Sized> Sync for Unique<T> {}
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: Sized> Unique<T> {
     /// Creates a new `Unique` that is dangling, but well-aligned.
     ///
@@ -78,7 +78,7 @@ impl<T: Sized> Unique<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> Unique<T> {
     /// Creates a new `Unique`.
     ///
@@ -133,7 +133,7 @@ impl<T: ?Sized> Unique<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> Clone for Unique<T> {
     #[inline]
     fn clone(&self) -> Self {
@@ -141,30 +141,30 @@ impl<T: ?Sized> Clone for Unique<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> Copy for Unique<T> {}
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized, U: ?Sized> CoerceUnsized<Unique<U>> for Unique<T> where T: Unsize<U> {}
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized, U: ?Sized> DispatchFromDyn<Unique<U>> for Unique<T> where T: Unsize<U> {}
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> fmt::Debug for Unique<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Pointer::fmt(&self.as_ptr(), f)
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> fmt::Pointer for Unique<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Pointer::fmt(&self.as_ptr(), f)
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> From<&mut T> for Unique<T> {
     #[inline]
     fn from(reference: &mut T) -> Self {
@@ -172,7 +172,7 @@ impl<T: ?Sized> From<&mut T> for Unique<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> From<&T> for Unique<T> {
     #[inline]
     fn from(reference: &T) -> Self {
@@ -180,7 +180,7 @@ impl<T: ?Sized> From<&T> for Unique<T> {
     }
 }
 
-#[unstable(feature = "ptr_internals", issue = "0")]
+#[unstable(feature = "ptr_internals", issue = "none")]
 impl<T: ?Sized> From<NonNull<T>> for Unique<T> {
     #[inline]
     fn from(p: NonNull<T>) -> Self {
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index 05baa1899b3..68e12e87789 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -38,7 +38,7 @@ use crate::ptr;
 use crate::mem;
 use crate::marker::{Copy, Send, Sync, Sized, self};
 
-#[unstable(feature = "slice_internals", issue = "0",
+#[unstable(feature = "slice_internals", issue = "none",
            reason = "exposed from core to be reused in std; use the memchr crate")]
 /// Pure rust memchr implementation, taken from rust-memchr
 pub mod memchr;
@@ -2723,12 +2723,12 @@ pub trait SliceIndex<T: ?Sized>: private_slice_index::Sealed {
 
     /// Returns a shared reference to the output at this location, if in
     /// bounds.
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     fn get(self, slice: &T) -> Option<&Self::Output>;
 
     /// Returns a mutable reference to the output at this location, if in
     /// bounds.
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     fn get_mut(self, slice: &mut T) -> Option<&mut Self::Output>;
 
     /// Returns a shared reference to the output at this location, without
@@ -2736,7 +2736,7 @@ pub trait SliceIndex<T: ?Sized>: private_slice_index::Sealed {
     /// Calling this method with an out-of-bounds index is *[undefined behavior]*
     /// even if the resulting reference is not used.
     /// [undefined behavior]: ../../reference/behavior-considered-undefined.html
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     unsafe fn get_unchecked(self, slice: &T) -> &Self::Output;
 
     /// Returns a mutable reference to the output at this location, without
@@ -2744,17 +2744,17 @@ pub trait SliceIndex<T: ?Sized>: private_slice_index::Sealed {
     /// Calling this method with an out-of-bounds index is *[undefined behavior]*
     /// even if the resulting reference is not used.
     /// [undefined behavior]: ../../reference/behavior-considered-undefined.html
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     unsafe fn get_unchecked_mut(self, slice: &mut T) -> &mut Self::Output;
 
     /// Returns a shared reference to the output at this location, panicking
     /// if out of bounds.
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     fn index(self, slice: &T) -> &Self::Output;
 
     /// Returns a mutable reference to the output at this location, panicking
     /// if out of bounds.
-    #[unstable(feature = "slice_index_methods", issue = "0")]
+    #[unstable(feature = "slice_index_methods", issue = "none")]
     fn index_mut(self, slice: &mut T) -> &mut Self::Output;
 }
 
@@ -5382,7 +5382,7 @@ pub fn from_mut<T>(s: &mut T) -> &mut [T] {
 }
 
 // This function is public only because there is no other way to unit test heapsort.
-#[unstable(feature = "sort_internals", reason = "internal to sort module", issue = "0")]
+#[unstable(feature = "sort_internals", reason = "internal to sort module", issue = "none")]
 #[doc(hidden)]
 pub fn heapsort<T, F>(v: &mut [T], mut is_less: F)
     where F: FnMut(&T, &T) -> bool
diff --git a/src/libcore/str/lossy.rs b/src/libcore/str/lossy.rs
index 762de0489a9..cf6ee6ed593 100644
--- a/src/libcore/str/lossy.rs
+++ b/src/libcore/str/lossy.rs
@@ -6,7 +6,7 @@ use crate::mem;
 // ignore-tidy-undocumented-unsafe
 
 /// Lossy UTF-8 string.
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 pub struct Utf8Lossy {
     bytes: [u8]
 }
@@ -27,13 +27,13 @@ impl Utf8Lossy {
 
 
 /// Iterator over lossy UTF-8 string
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 #[allow(missing_debug_implementations)]
 pub struct Utf8LossyChunksIter<'a> {
     source: &'a [u8],
 }
 
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 #[derive(PartialEq, Eq, Debug)]
 pub struct Utf8LossyChunk<'a> {
     /// Sequence of valid chars.
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index e2cc99813ac..15b65ed7655 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -21,7 +21,7 @@ use crate::option;
 
 pub mod pattern;
 
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 #[allow(missing_docs)]
 pub mod lossy;
 
@@ -496,7 +496,7 @@ fn unwrap_or_0(opt: Option<&u8>) -> u8 {
 
 /// Reads the next code point out of a byte iterator (assuming a
 /// UTF-8-like encoding).
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 #[inline]
 pub fn next_code_point<'a, I: Iterator<Item = &'a u8>>(bytes: &mut I) -> Option<u32> {
     // Decode UTF-8
@@ -1583,7 +1583,7 @@ static UTF8_CHAR_WIDTH: [u8; 256] = [
 ];
 
 /// Given a first byte, determines how many bytes are in this UTF-8 character.
-#[unstable(feature = "str_internals", issue = "0")]
+#[unstable(feature = "str_internals", issue = "none")]
 #[inline]
 pub fn utf8_char_width(b: u8) -> usize {
     UTF8_CHAR_WIDTH[b as usize] as usize
diff --git a/src/libcore/unicode/mod.rs b/src/libcore/unicode/mod.rs
index a3ec9fd51f0..e424174f554 100644
--- a/src/libcore/unicode/mod.rs
+++ b/src/libcore/unicode/mod.rs
@@ -1,4 +1,4 @@
-#![unstable(feature = "unicode_internals", issue = "0")]
+#![unstable(feature = "unicode_internals", issue = "none")]
 #![allow(missing_docs)]
 
 mod bool_trie;