Fix review comments

Author: bjorn3

compiler/rustc_ast/src/expand/allocator.rs

@@ -18,6 +18,7 @@ pub fn default_fn_name(base: Symbol) -> String {
 pub const ALLOC_ERROR_HANDLER: Symbol = sym::alloc_error_handler;
 pub const NO_ALLOC_SHIM_IS_UNSTABLE: &str = "__rust_no_alloc_shim_is_unstable_v2";
 
+/// Argument or return type for methods in the allocator shim
 #[derive(Copy, Clone)]
 pub enum AllocatorTy {
     Layout,

compiler/rustc_codegen_ssa/src/base.rs

@@ -664,8 +664,8 @@ pub fn allocator_shim_contents(tcx: TyCtxt<'_>, kind: AllocatorKind) -> Vec<Allo
         methods.extend(ALLOCATOR_METHODS.into_iter().copied());
     }
 
-    // If allocator_kind is Some then alloc_error_handler_kind must
-    // also be Some.
+    // If the return value of allocator_kind_for_codegen is Some then
+    // alloc_error_handler_kind must also be Some.
     if tcx.alloc_error_handler_kind(()).unwrap() == AllocatorKind::Default {
         methods.push(AllocatorMethod {
             name: ALLOC_ERROR_HANDLER,

compiler/rustc_metadata/src/creader.rs

@@ -1087,17 +1087,15 @@ impl CStore {
                 }
                 spans => !spans.is_empty(),
             };
-        self.has_alloc_error_handler =
-            match &*fn_spans(krate, Symbol::intern(&global_fn_name(ALLOC_ERROR_HANDLER))) {
-                [span1, span2, ..] => {
-                    tcx.dcx().emit_err(errors::NoMultipleAllocErrorHandler {
-                        span2: *span2,
-                        span1: *span1,
-                    });
-                    true
-                }
-                spans => !spans.is_empty(),
-            };
+        let alloc_error_handler = Symbol::intern(&global_fn_name(ALLOC_ERROR_HANDLER));
+        self.has_alloc_error_handler = match &*fn_spans(krate, alloc_error_handler) {
+            [span1, span2, ..] => {
+                tcx.dcx()
+                    .emit_err(errors::NoMultipleAllocErrorHandler { span2: *span2, span1: *span1 });
+                true
+            }
+            spans => !spans.is_empty(),
+        };
 
         // Check to see if we actually need an allocator. This desire comes
         // about through the `#![needs_allocator]` attribute and is typically