[es6] When comparing two symbols we may need to throw a TypeError

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 401db6b3fbfc6af98c7f0e3eee01997106eb3127..7a9c12e2d2f95b037af33b2c3e950f866cfddd03 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -1578,6 +1578,9 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) {
       // Call runtime on identical objects.  Otherwise return equal.
       __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rcx);
       __ j(above_equal, &not_identical, Label::kNear);
+      // Call runtime on identical symbols since we need to throw a TypeError.
+      __ CmpObjectType(rax, SYMBOL_TYPE, rcx);
+      __ j(equal, &not_identical, Label::kNear);
     }
     __ Set(rax, EQUAL);
     __ ret(0);