Auto merge of #98224 - eddyb:proc-macro-spurious-repr, r=bjorn3

proc_macro/bridge: remove `#[repr(C)]` from non-ABI-relevant types.

Not sure how this happened, maybe some of these were passed through the bridge a long time ago?

r? `@bjorn3`

library/proc_macro/src/bridge/client.rs

@@ -29,7 +29,6 @@ extern "C" fn get() -> &'static Self {
         }
 
         // FIXME(eddyb) generate the definition of `HandleStore` in `server.rs`.
-        #[repr(C)]
         #[allow(non_snake_case)]
         pub(super) struct HandleStore<S: server::Types> {
             $($oty: handle::OwnedStore<S::$oty>,)*
@@ -46,7 +45,6 @@ pub(super) fn new(handle_counters: &'static HandleCounters) -> Self {
         }
 
         $(
-            #[repr(C)]
             pub(crate) struct $oty {
                 handle: handle::Handle,
                 // Prevent Send and Sync impls. `!Send`/`!Sync` is the usual
@@ -131,7 +129,6 @@ fn decode(r: &mut Reader<'_>, s: &mut S) -> Self {
         )*
 
         $(
-            #[repr(C)]
             #[derive(Copy, Clone, PartialEq, Eq, Hash)]
             pub(crate) struct $ity {
                 handle: handle::Handle,