Change more x64 size checks to not apply to x32.

Commit 95e096d6 changed a bunch of size checks already, but more have
been added, so this fixes the new ones the same way: the various size
checks that are conditional on target_arch = "x86_64" were not intended
to apply to x86_64-unknown-linux-gnux32, so add
target_pointer_width = "64" to the conditions.

src/librustdoc/html/render/context.rs

@@ -69,7 +69,7 @@ crate struct Context<'tcx> {
 }
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 rustc_data_structures::static_assert_size!(Context<'_>, 104);
 
 /// Shared mutable state used in [`Context`] and elsewhere.