Rollup merge of #60959 - petrochenkov:sassert, r=estebank

rustc: Improve type size assertions

Now they
- Tell what the new size is, when it changes
- Do not require passing an identifier

```
   ::: src\libsyntax\parse\token.rs:223:1
    |
223 |    static_assert_size!(Token, 123);
    |    -------------------------------- in this macro invocation
    |
    = note: expected type `[(); 123]`
               found type `[(); 16]`
```

3 files changed, 7 insertions, 7 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index d12240655e6..b55ca453fb3 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -16,7 +16,7 @@ use crate::ThinVec;
 
 use rustc_data_structures::indexed_vec::Idx;
 #[cfg(target_arch = "x86_64")]
-use rustc_data_structures::static_assert;
+use rustc_data_structures::static_assert_size;
 use rustc_target::spec::abi::Abi;
 use syntax_pos::{Span, DUMMY_SP};
 
@@ -964,7 +964,7 @@ pub struct Expr {
 
 // `Expr` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(target_arch = "x86_64")]
-static_assert!(MEM_SIZE_OF_EXPR: std::mem::size_of::<Expr>() == 96);
+static_assert_size!(Expr, 96);
 
 impl Expr {
     /// Whether this expression would be valid somewhere that expects a value; for example, an `if`
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 049fb6cb78b..068fc41c87a 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -19,7 +19,7 @@ use log::info;
 use std::fmt;
 use std::mem;
 #[cfg(target_arch = "x86_64")]
-use rustc_data_structures::static_assert;
+use rustc_data_structures::static_assert_size;
 use rustc_data_structures::sync::Lrc;
 
 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
@@ -74,7 +74,7 @@ pub enum Lit {
 }
 
 #[cfg(target_arch = "x86_64")]
-static_assert!(MEM_SIZE_OF_LIT: mem::size_of::<Lit>() == 8);
+static_assert_size!(Lit, 8);
 
 impl Lit {
     crate fn literal_name(&self) -> &'static str {
@@ -220,7 +220,7 @@ pub enum Token {
 
 // `Token` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(target_arch = "x86_64")]
-static_assert!(MEM_SIZE_OF_STATEMENT: mem::size_of::<Token>() == 16);
+static_assert_size!(Token, 16);
 
 impl Token {
     /// Recovers a `Token` from an `ast::Ident`. This creates a raw identifier if necessary.
diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
index 93b5ecadd14..3cb16c30a50 100644
--- a/src/libsyntax/tokenstream.rs
+++ b/src/libsyntax/tokenstream.rs
@@ -21,7 +21,7 @@ use crate::print::pprust;
 
 use syntax_pos::{BytePos, Mark, Span, DUMMY_SP};
 #[cfg(target_arch = "x86_64")]
-use rustc_data_structures::static_assert;
+use rustc_data_structures::static_assert_size;
 use rustc_data_structures::sync::Lrc;
 use serialize::{Decoder, Decodable, Encoder, Encodable};
 use smallvec::{SmallVec, smallvec};
@@ -158,7 +158,7 @@ pub type TreeAndJoint = (TokenTree, IsJoint);
 
 // `TokenStream` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(target_arch = "x86_64")]
-static_assert!(MEM_SIZE_OF_TOKEN_STREAM: mem::size_of::<TokenStream>() == 8);
+static_assert_size!(TokenStream, 8);
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum IsJoint {