MIPS: ES6 symbols: Implement Symbol intrinsic and basic functionality

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index f32b779578fa906d105b9f56259e82c17db9c0e9..75c459f405c7ff6e5213123aabffa93c1bcea4ed 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1072,9 +1072,13 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
 
     // If the type of the result (stored in its map) is less than
     // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
-    __ GetObjectType(v0, a3, a3);
+    __ GetObjectType(v0, a1, a3);
     __ Branch(&exit, greater_equal, a3, Operand(FIRST_SPEC_OBJECT_TYPE));
 
+    // Symbols are "objects".
+    __ lbu(a3, FieldMemOperand(a1, Map::kInstanceTypeOffset));
+    __ Branch(&exit, eq, a3, Operand(SYMBOL_TYPE));
+
     // Throw away the result of the constructor invocation and use the
     // on-stack receiver as the result.
     __ bind(&use_receiver);