Merge pull request #66513 from xedin/init-accessor-diagnostics

[Sema/SIL] Improve diagnostics related to init accessors

lib/Sema/CSDiagnostics.cpp

@@ -9059,3 +9059,8 @@ bool MissingEachForValuePackReference::diagnoseAsError() {
 
   return true;
 }
+
+bool InvalidMemberReferenceWithinInitAccessor::diagnoseAsError() {
+  emitDiagnostic(diag::init_accessor_invalid_member_ref, MemberName);
+  return true;
+}