Use a different map to distinguish eval contexts

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index d63453676f4cbbb81b69a3b1176bc4ab7eff64c2..68e12a20be9a5790c26530f240e6d7f3d18a4348 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -2629,10 +2629,13 @@ void FastNewClosureStub::GenerateAssembly(CodeStubAssembler* assembler) const {
       Generate(assembler, assembler->Parameter(0), assembler->Parameter(1)));
 }
 
-// static
-compiler::Node* FastNewFunctionContextStub::Generate(
-    CodeStubAssembler* assembler, compiler::Node* function,
-    compiler::Node* slots, compiler::Node* context) {
+namespace {
+
+compiler::Node* GenerateFastNewFunctionContextStub(CodeStubAssembler* assembler,
+                                                   compiler::Node* function,
+                                                   compiler::Node* slots,
+                                                   compiler::Node* context,
+                                                   Handle<Map> map) {
   typedef compiler::Node Node;
 
   Node* min_context_slots =
@@ -2646,9 +2649,8 @@ compiler::Node* FastNewFunctionContextStub::Generate(
   Node* function_context = assembler->Allocate(size);
 
   Isolate* isolate = assembler->isolate();
-  assembler->StoreMapNoWriteBarrier(
-      function_context,
-      assembler->HeapConstant(isolate->factory()->function_context_map()));
+  assembler->StoreMapNoWriteBarrier(function_context,
+                                    assembler->HeapConstant(map));
   assembler->StoreObjectFieldNoWriteBarrier(function_context,
                                             Context::kLengthOffset,
                                             assembler->SmiFromWord32(length));
@@ -2682,6 +2684,17 @@ compiler::Node* FastNewFunctionContextStub::Generate(
   return function_context;
 }
 
+}  // namespace
+
+// static
+compiler::Node* FastNewFunctionContextStub::Generate(
+    CodeStubAssembler* assembler, compiler::Node* function,
+    compiler::Node* slots, compiler::Node* context) {
+  Handle<Map> map = assembler->isolate()->factory()->function_context_map();
+  return GenerateFastNewFunctionContextStub(assembler, function, slots, context,
+                                            map);
+}
+
 void FastNewFunctionContextStub::GenerateAssembly(
     CodeStubAssembler* assembler) const {
   typedef compiler::Node Node;
@@ -2693,6 +2706,26 @@ void FastNewFunctionContextStub::GenerateAssembly(
 }
 
 // static
+compiler::Node* FastNewEvalContextStub::Generate(CodeStubAssembler* assembler,
+                                                 compiler::Node* function,
+                                                 compiler::Node* slots,
+                                                 compiler::Node* context) {
+  Handle<Map> map = assembler->isolate()->factory()->eval_context_map();
+  return GenerateFastNewFunctionContextStub(assembler, function, slots, context,
+                                            map);
+}
+
+void FastNewEvalContextStub::GenerateAssembly(
+    CodeStubAssembler* assembler) const {
+  typedef compiler::Node Node;
+  Node* function = assembler->Parameter(Descriptor::kFunction);
+  Node* slots = assembler->Parameter(FastNewFunctionContextDescriptor::kSlots);
+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  assembler->Return(Generate(assembler, function, slots, context));
+}
+
+// static
 compiler::Node* FastCloneRegExpStub::Generate(CodeStubAssembler* assembler,
                                               compiler::Node* closure,
                                               compiler::Node* literal_index,