Use a different map to distinguish eval contexts

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index b74aabbc825c0223b6b6e87315334db081620e0c..98c78d3f7487d4bfac8c1e862360f17852c7c185 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -861,17 +861,22 @@ class FastNewClosureStub : public TurboFanCodeStub {
 
 class FastNewFunctionContextStub final : public TurboFanCodeStub {
  public:
-  explicit FastNewFunctionContextStub(Isolate* isolate)
-      : TurboFanCodeStub(isolate) {}
+  explicit FastNewFunctionContextStub(Isolate* isolate, bool for_eval)
+      : TurboFanCodeStub(isolate) {
+    minor_key_ = ForEvalBits::encode(for_eval);
+  }
 
   static compiler::Node* Generate(CodeStubAssembler* assembler,
                                   compiler::Node* function,
                                   compiler::Node* slots,
-                                  compiler::Node* context);
+                                  compiler::Node* context, bool for_eval);
 
  private:
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewFunctionContext);
   DEFINE_TURBOFAN_CODE_STUB(FastNewFunctionContext, TurboFanCodeStub);
+
+  int for_eval() const { return ForEvalBits::decode(minor_key_); }
+  class ForEvalBits : public BitField<bool, 0, 1> {};
 };