fix parser size

Author: chenyukang

compiler/rustc_parse/src/parser/mod.rs

@@ -162,7 +162,7 @@ pub struct Parser<'a> {
 // This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure
 // it doesn't unintentionally get bigger.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Parser<'_>, 320);
+rustc_data_structures::static_assert_size!(Parser<'_>, 272);
 
 /// Stores span information about a closure.
 #[derive(Clone)]