Avoid LocalCopy instantiation for #[inline] on -Copt-level=0

Because it is not really helpful to have downstream instantiations that
we won't inline anyways (`*`)

`*` This is not quite true when `#[inline]` is being used as effectively
`#[likely_unused]`

Author: Noratrieb

compiler/rustc_mir_transform/src/cross_crate_inline.rs

@@ -46,7 +46,9 @@ fn cross_crate_inlinable(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
     // #[inline(never)] to force code generation.
     match codegen_fn_attrs.inline {
         InlineAttr::Never => return false,
-        InlineAttr::Hint | InlineAttr::Always | InlineAttr::Force { .. } => return true,
+        // For -Copt-level=0, we won't inline functions anyways, so there's no reason to codegen them as LocalCopy.
+        InlineAttr::Hint if tcx.sess.opts.optimize != OptLevel::No => return true,
+        InlineAttr::Always | InlineAttr::Force { .. } => return true,
         _ => {}
     }