Reorganize object type enum, such that proxies are no longer in the middle

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 25863ed08e71d4677795efa632cba03e0cb468c9..0702803bd788b47ee53a5098916387e32c902148 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1753,28 +1753,36 @@ void LCodeGen::EmitClassOfTest(Label* is_true,
                                Register input,
                                Register temp) {
   __ JumpIfSmi(input, is_false);
-  __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
-  __ j(below, is_false);
 
-  // Map is now in temp.
+  // Assuming the following assertions, we can do the same test for
+  // either "Object" or "Function", only the branch conditions differ.
+  STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+  STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                FIRST_SPEC_OBJECT_TYPE + 1);
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                LAST_SPEC_OBJECT_TYPE - 1);
+  STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+
   // Functions have class 'Function'.
-  __ CmpInstanceType(temp, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
+  __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
+  // Map is now in temp.
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ j(above_equal, is_true);
+    __ j(below, is_false);
+    __ j(equal, is_true);
+  } else {
+    __ j(below_equal, is_false);
+  }
+  __ CmpInstanceType(temp, LAST_SPEC_OBJECT_TYPE);
+  if (class_name->IsEqualTo(CStrVector("Function"))) {
+    __ j(equal, is_true);
   } else {
     __ j(above_equal, is_false);
   }
 
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   __ movq(temp, FieldOperand(temp, Map::kConstructorOffset));
 
-  // As long as LAST_CALLABLE_SPEC_OBJECT_TYPE is the last type and
-  // FIRST_CALLABLE_SPEC_OBJECT_TYPE comes right after
-  // LAST_NONCALLABLE_SPEC_OBJECT_TYPE, we can avoid checking for the latter.
-  STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
-  STATIC_ASSERT(FIRST_CALLABLE_SPEC_OBJECT_TYPE ==
-                LAST_NONCALLABLE_SPEC_OBJECT_TYPE + 1);
-
   // Objects with a non-function constructor have class 'Object'.
   __ CmpObjectType(temp, JS_FUNCTION_TYPE, kScratchRegister);
   if (class_name->IsEqualTo(CStrVector("Object"))) {
@@ -3980,9 +3988,12 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     final_branch_condition = not_zero;
 
   } else if (type_name->Equals(heap()->function_symbol())) {
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label);
-    __ CmpObjectType(input, FIRST_CALLABLE_SPEC_OBJECT_TYPE, input);
-    final_branch_condition = above_equal;
+    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
+    __ j(equal, true_label);
+    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
+    final_branch_condition = equal;
 
   } else if (type_name->Equals(heap()->object_symbol())) {
     __ JumpIfSmi(input, false_label);