Revert merges of r12531 and r12562 from 3.12 branch, going back to 3.12.19.12

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index c548f7257dbee3939439fcabd3a26319de2fdb42..40c5e4ecc7b510329c8f059b66fec60a2f425f99 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1683,15 +1683,15 @@ class JSObject: public JSReceiver {
       String* name,
       PropertyAttributes* attributes);
   MUST_USE_RESULT MaybeObject* GetPropertyWithInterceptor(
-      Object* receiver,
+      JSReceiver* receiver,
       String* name,
       PropertyAttributes* attributes);
   MUST_USE_RESULT MaybeObject* GetPropertyPostInterceptor(
-      Object* receiver,
+      JSReceiver* receiver,
       String* name,
       PropertyAttributes* attributes);
   MUST_USE_RESULT MaybeObject* GetLocalPropertyPostInterceptor(
-      Object* receiver,
+      JSReceiver* receiver,
       String* name,
       PropertyAttributes* attributes);