Rollup merge of #82841 - hvdijk:x32, r=joshtriplett

Change x64 size checks to not apply to x32.

Rust contains various size checks conditional on target_arch = "x86_64", but these checks were never intended to apply to x86_64-unknown-linux-gnux32. Add target_pointer_width = "64" to the conditions.

compiler/rustc_mir_build/src/thir/mod.rs

@@ -96,7 +96,7 @@ crate enum StmtKind<'tcx> {
 }
 
 // `Expr` is used a lot. Make sure it doesn't unintentionally get bigger.
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 rustc_data_structures::static_assert_size!(Expr<'_>, 168);
 
 /// The Thir trait implementor lowers their expressions (`&'tcx H::Expr`)