Simplify static_assert_sizes.

We want to run them on all 64-bit platforms.

compiler/rustc_parse/src/parser/mod.rs

@@ -179,7 +179,7 @@ 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(any(target_arch = "x86_64", target_arch = "aarch64"), target_pointer_width = "64"))]
+#[cfg(target_pointer_width = "64")]
 rustc_data_structures::static_assert_size!(Parser<'_>, 264);
 
 /// Stores span information about a closure.