MIPS: Use SmiTst and TrySmiTag MacroAssembler instructions.

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 2fe081ee676bd1ee76d7f871c20271c596322524..e7105ba3358e5f7711dcbda315b790b1e6b3b447 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -122,7 +122,7 @@ void Builtins::Generate_InternalArrayCode(MacroAssembler* masm) {
   if (FLAG_debug_code) {
     // Initial map for the builtin InternalArray functions should be maps.
     __ lw(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
-    __ And(t0, a2, Operand(kSmiTagMask));
+    __ SmiTst(a2, t0);
     __ Assert(ne, kUnexpectedInitialMapForInternalArrayFunction,
               t0, Operand(zero_reg));
     __ GetObjectType(a2, a3, t0);
@@ -152,7 +152,7 @@ void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
   if (FLAG_debug_code) {
     // Initial map for the builtin Array functions should be maps.
     __ lw(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
-    __ And(t0, a2, Operand(kSmiTagMask));
+    __ SmiTst(a2, t0);
     __ Assert(ne, kUnexpectedInitialMapForArrayFunction1,
               t0, Operand(zero_reg));
     __ GetObjectType(a2, a3, t0);