Auto merge of #66824 - tmandry:rollup-kk56bte, r=tmandry

Rollup of 17 pull requests

Successful merges:

 - #64325 (Stabilize nested self receivers in 1.41.0)
 - #66222 (Use `eq_opaque_type_and_type` when type-checking closure signatures)
 - #66305 (Add by-value arrays to `improper_ctypes` lint)
 - #66399 (rustc_metadata: simplify the interactions between Lazy and Table.)
 - #66534 (Allow global references via ForeignItem and Item for the same symbol name during LLVM codegen)
 - #66700 (Fix pointing at arg for fulfillment errors in function calls)
 - #66704 (Intra doc enum variant field)
 - #66718 (Refactor `parse_enum_item` to use `parse_delim_comma_seq`)
 - #66722 (Handle non_exhaustive in borrow checking)
 - #66744 (Fix shrink_to panic documentation)
 - #66761 (Use LLVMDisposePassManager instead of raw delete in rustllvm)
 - #66769 (Add core::{f32,f64}::consts::TAU.)
 - #66774 (Clean up error codes)
 - #66777 (Put back tidy check on error codes)
 - #66797 (Fixes small typo in array docs r? @steveklabnik)
 - #66798 (Fix spelling typos)
 - #66800 (Combine similar tests for const match)

Failed merges:

r? @ghost

18 files changed, 60 insertions, 54 deletions

diff --git a/src/librustc_error_codes/error_codes/E0015.md b/src/librustc_error_codes/error_codes/E0015.md
index 361cb425809..021a0219d13 100644
--- a/src/librustc_error_codes/error_codes/E0015.md
+++ b/src/librustc_error_codes/error_codes/E0015.md
@@ -1,4 +1,5 @@
-A constant item was initialized with something that is not a constant expression.
+A constant item was initialized with something that is not a constant
+expression.
 
 Erroneous code example:
 
diff --git a/src/librustc_error_codes/error_codes/E0071.md b/src/librustc_error_codes/error_codes/E0071.md
index 768dd0c7a48..bc2c03a0220 100644
--- a/src/librustc_error_codes/error_codes/E0071.md
+++ b/src/librustc_error_codes/error_codes/E0071.md
@@ -1,5 +1,5 @@
-You tried to use structure-literal syntax to create an item that is
-not a structure or enum variant.
+A structure-literal syntax was used to create an item that is not a structure
+or enum variant.
 
 Example of erroneous code:
 
@@ -9,8 +9,8 @@ let t = U32 { value: 4 }; // error: expected struct, variant or union type,
                           // found builtin type `u32`
 ```
 
-To fix this, ensure that the name was correctly spelled, and that
-the correct form of initializer was used.
+To fix this, ensure that the name was correctly spelled, and that the correct
+form of initializer was used.
 
 For example, the code above can be fixed to:
 
diff --git a/src/librustc_error_codes/error_codes/E0072.md b/src/librustc_error_codes/error_codes/E0072.md
index e461d45f30c..8f7749abab1 100644
--- a/src/librustc_error_codes/error_codes/E0072.md
+++ b/src/librustc_error_codes/error_codes/E0072.md
@@ -1,20 +1,23 @@
-When defining a recursive struct or enum, any use of the type being defined
-from inside the definition must occur behind a pointer (like `Box` or `&`).
-This is because structs and enums must have a well-defined size, and without
-the pointer, the size of the type would need to be unbounded.
+A recursive type has infinite size because it doesn't have an indirection.
 
-Consider the following erroneous definition of a type for a list of bytes:
+Erroneous code example:
 
 ```compile_fail,E0072
-// error, invalid recursive struct type
 struct ListNode {
     head: u8,
-    tail: Option<ListNode>,
+    tail: Option<ListNode>, // error: no indirection here so impossible to
+                            //        compute the type's size
 }
 ```
 
-This type cannot have a well-defined size, because it needs to be arbitrarily
-large (since we would be able to nest `ListNode`s to any depth). Specifically,
+When defining a recursive struct or enum, any use of the type being defined
+from inside the definition must occur behind a pointer (like `Box`, `&` or
+`Rc`). This is because structs and enums must have a well-defined size, and
+without the pointer, the size of the type would need to be unbounded.
+
+In the example, the type cannot have a well-defined size, because it needs to be
+arbitrarily large (since we would be able to nest `ListNode`s to any depth).
+Specifically,
 
 ```plain
 size of `ListNode` = 1 byte for `head`
diff --git a/src/librustc_error_codes/error_codes/E0075.md b/src/librustc_error_codes/error_codes/E0075.md
index f15af8150ba..969c1ee7131 100644
--- a/src/librustc_error_codes/error_codes/E0075.md
+++ b/src/librustc_error_codes/error_codes/E0075.md
@@ -1,21 +1,23 @@
-The `#[simd]` attribute can only be applied to non empty tuple structs, because
-it doesn't make sense to try to use SIMD operations when there are no values to
-operate on.
+A `#[simd]` attribute was applied to an empty tuple struct.
 
-This will cause an error:
+Erroneous code example:
 
 ```compile_fail,E0075
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Bad;
+struct Bad; // error!
 ```
 
-This will not:
+The `#[simd]` attribute can only be applied to non empty tuple structs, because
+it doesn't make sense to try to use SIMD operations when there are no values to
+operate on.
+
+Fixed example:
 
 ```
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Good(u32);
+struct Good(u32); // ok!
 ```
diff --git a/src/librustc_error_codes/error_codes/E0076.md b/src/librustc_error_codes/error_codes/E0076.md
index 466e0a96e6b..f293a2a5772 100644
--- a/src/librustc_error_codes/error_codes/E0076.md
+++ b/src/librustc_error_codes/error_codes/E0076.md
@@ -1,21 +1,24 @@
-When using the `#[simd]` attribute to automatically use SIMD operations in tuple
-struct, the types in the struct must all be of the same type, or the compiler
-will trigger this error.
+All types in a tuple struct aren't the same when using the `#[simd]`
+attribute.
 
-This will cause an error:
+Erroneous code example:
 
 ```compile_fail,E0076
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Bad(u16, u32, u32);
+struct Bad(u16, u32, u32); // error!
 ```
 
-This will not:
+When using the `#[simd]` attribute to automatically use SIMD operations in tuple
+struct, the types in the struct must all be of the same type, or the compiler
+will trigger this error.
+
+Fixed example:
 
 ```
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Good(u32, u32, u32);
+struct Good(u32, u32, u32); // ok!
 ```
diff --git a/src/librustc_error_codes/error_codes/E0077.md b/src/librustc_error_codes/error_codes/E0077.md
index 6ae35a6aa17..b14513c6ccf 100644
--- a/src/librustc_error_codes/error_codes/E0077.md
+++ b/src/librustc_error_codes/error_codes/E0077.md
@@ -1,20 +1,23 @@
-When using the `#[simd]` attribute on a tuple struct, the elements in the tuple
-must be machine types so SIMD operations can be applied to them.
+A tuple struct's element isn't a machine type when using the `#[simd]`
+attribute.
 
-This will cause an error:
+Erroneous code example:
 
 ```compile_fail,E0077
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Bad(String);
+struct Bad(String); // error!
 ```
 
-This will not:
+When using the `#[simd]` attribute on a tuple struct, the elements in the tuple
+must be machine types so SIMD operations can be applied to them.
+
+Fixed example:
 
 ```
 #![feature(repr_simd)]
 
 #[repr(simd)]
-struct Good(u32, u32, u32);
+struct Good(u32, u32, u32); // ok!
 ```
diff --git a/src/librustc_error_codes/error_codes/E0107.md b/src/librustc_error_codes/error_codes/E0107.md
index 3a8acba061c..bfe0d21f312 100644
--- a/src/librustc_error_codes/error_codes/E0107.md
+++ b/src/librustc_error_codes/error_codes/E0107.md
@@ -25,4 +25,3 @@ fn main() {
                     //        expected 0, found 1
 }
 ```
-
diff --git a/src/librustc_error_codes/error_codes/E0307.md b/src/librustc_error_codes/error_codes/E0307.md
index c382f406e4b..1779e5dbb30 100644
--- a/src/librustc_error_codes/error_codes/E0307.md
+++ b/src/librustc_error_codes/error_codes/E0307.md
@@ -1,5 +1,5 @@
 This error indicates that the `self` parameter in a method has an invalid
-"reciever type".
+"receiver type".
 
 Methods take a special first parameter, of which there are three variants:
 `self`, `&self`, and `&mut self`. These are syntactic sugar for
diff --git a/src/librustc_error_codes/error_codes/E0369.md b/src/librustc_error_codes/error_codes/E0369.md
index 08db342428c..397979e5641 100644
--- a/src/librustc_error_codes/error_codes/E0369.md
+++ b/src/librustc_error_codes/error_codes/E0369.md
@@ -26,4 +26,3 @@ left and may require reallocation. This requires ownership of the string
 on the left. If something should be added to a string literal, move the
 literal to the heap by allocating it with `to_owned()` like in
 `"Your text".to_owned()`.
-
diff --git a/src/librustc_error_codes/error_codes/E0404.md b/src/librustc_error_codes/error_codes/E0404.md
index 861a50bfd8c..201107c05a0 100644
--- a/src/librustc_error_codes/error_codes/E0404.md
+++ b/src/librustc_error_codes/error_codes/E0404.md
@@ -41,4 +41,3 @@ trait Foo {
 
 fn bar<T: Foo>(t: T) {} // ok!
 ```
-
diff --git a/src/librustc_error_codes/error_codes/E0458.md b/src/librustc_error_codes/error_codes/E0458.md
index e6baeb8f692..385079d403d 100644
--- a/src/librustc_error_codes/error_codes/E0458.md
+++ b/src/librustc_error_codes/error_codes/E0458.md
@@ -10,4 +10,3 @@ Please specify a valid "kind" value, from one of the following:
 * static
 * dylib
 * framework
-
diff --git a/src/librustc_error_codes/error_codes/E0633.md b/src/librustc_error_codes/error_codes/E0633.md
index a68da1188b5..65cdf90036a 100644
--- a/src/librustc_error_codes/error_codes/E0633.md
+++ b/src/librustc_error_codes/error_codes/E0633.md
@@ -21,4 +21,3 @@ The `#[unwind]` attribute should be used as follows:
 
 NB. The default behavior here is "allowed", but this is unspecified
 and likely to change in the future.
-
diff --git a/src/librustc_error_codes/error_codes/E0635.md b/src/librustc_error_codes/error_codes/E0635.md
index 2382ce0d3ff..a39d2be4f8f 100644
--- a/src/librustc_error_codes/error_codes/E0635.md
+++ b/src/librustc_error_codes/error_codes/E0635.md
@@ -5,4 +5,3 @@ Erroneous code example:
 ```compile_fail,E0635
 #![feature(nonexistent_rust_feature)] // error: unknown feature
 ```
-
diff --git a/src/librustc_error_codes/error_codes/E0636.md b/src/librustc_error_codes/error_codes/E0636.md
index dabf9b64123..57cf72db556 100644
--- a/src/librustc_error_codes/error_codes/E0636.md
+++ b/src/librustc_error_codes/error_codes/E0636.md
@@ -7,4 +7,3 @@ Erroneous code example:
 #![feature(rust1)]
 #![feature(rust1)] // error: the feature `rust1` has already been declared
 ```
-
diff --git a/src/librustc_error_codes/error_codes/E0641.md b/src/librustc_error_codes/error_codes/E0641.md
index e39bebce1fe..e2110042c7e 100644
--- a/src/librustc_error_codes/error_codes/E0641.md
+++ b/src/librustc_error_codes/error_codes/E0641.md
@@ -16,4 +16,4 @@ let a = &(String::from("Hello world!")) as *const _; // Ok
 let b = 0 as *const i32; // Ok
 
 let c: *const i32 = 0 as *const _; // Ok
-```
\ No newline at end of file
+```
diff --git a/src/librustc_error_codes/error_codes/E0644.md b/src/librustc_error_codes/error_codes/E0644.md
index 61acb084a45..7a653bd2264 100644
--- a/src/librustc_error_codes/error_codes/E0644.md
+++ b/src/librustc_error_codes/error_codes/E0644.md
@@ -27,4 +27,3 @@ closure call itself by capturing a `&Fn()` object or `fn()` pointer
 that refers to itself. That is permitting, since the closure would be
 invoking itself via a virtual call, and hence does not directly
 reference its own *type*.
-
diff --git a/src/librustc_error_codes/error_codes/E0706.md b/src/librustc_error_codes/error_codes/E0706.md
index bee9219af7c..d379b8a2384 100644
--- a/src/librustc_error_codes/error_codes/E0706.md
+++ b/src/librustc_error_codes/error_codes/E0706.md
@@ -1,4 +1,4 @@
- `async fn`s are not yet supported in traits in Rust.
+`async fn`s are not yet supported in traits in Rust.
 
 Erroneous code example:
 
@@ -10,7 +10,8 @@ trait T {
 }
 ```
 
-`async fn`s return an `impl Future`, making the following two examples equivalent:
+`async fn`s return an `impl Future`, making the following two examples
+equivalent:
 
 ```edition2018,ignore (example-of-desugaring-equivalence)
 async fn foo() -> User {
@@ -23,8 +24,8 @@ fn foo(&self) -> impl Future<Output = User> + '_ {
 ```
 
 But when it comes to supporting this in traits, there are [a few implementation
-issues][async-is-hard]. One of them is returning `impl Trait` in traits is not supported,
-as it would require [Generic Associated Types] to be supported:
+issues][async-is-hard]. One of them is returning `impl Trait` in traits is not
+supported, as it would require [Generic Associated Types] to be supported:
 
 ```edition2018,ignore (example-of-desugaring-equivalence)
 impl MyDatabase {
@@ -40,13 +41,14 @@ impl MyDatabase {
 }
 ```
 
-Until these issues are resolved, you can use the [`async-trait` crate], allowing you to use
-`async fn` in traits by desugaring to "boxed futures"
+Until these issues are resolved, you can use the [`async-trait` crate], allowing
+you to use `async fn` in traits by desugaring to "boxed futures"
 (`Pin<Box<dyn Future + Send + 'async>>`).
 
-Note that using these trait methods will result in a heap allocation per-function-call. This is not
-a significant cost for the vast majority of applications, but should be considered when deciding
-whether to use this functionality in the public API of a low-level function that is expected to be
+Note that using these trait methods will result in a heap allocation
+per-function-call. This is not a significant cost for the vast majority of
+applications, but should be considered when deciding whether to use this
+functionality in the public API of a low-level function that is expected to be
 called millions of times a second.
 
 You might be interested in visiting the [async book] for further information.
diff --git a/src/librustc_error_codes/error_codes/E0745.md b/src/librustc_error_codes/error_codes/E0745.md
index 7c478a1e0c8..39bebdcd375 100644
--- a/src/librustc_error_codes/error_codes/E0745.md
+++ b/src/librustc_error_codes/error_codes/E0745.md
@@ -11,7 +11,7 @@ fn temp_address() {
 
 To avoid the error, first bind the temporary to a named local variable.
 
-```ignore
+```ignore (not yet implemented)
 # #![feature(raw_ref_op)]
 fn temp_address() {
     let val = 2;