Replace nonexistent a4 by t0 on mips.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 161d73d16477eff0e26250454f94085233edeaa6..68cab0cab653658f4dc0d574aeb58100443665c2 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -3258,11 +3258,11 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
     if (NeedsChecks()) {
       // Do not transform the receiver for strict mode functions and natives.
       __ lw(a3, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-      __ lw(a4, FieldMemOperand(a3, SharedFunctionInfo::kCompilerHintsOffset));
+      __ lw(t0, FieldMemOperand(a3, SharedFunctionInfo::kCompilerHintsOffset));
       int32_t strict_mode_function_mask =
           1 <<  (SharedFunctionInfo::kStrictModeFunction + kSmiTagSize);
       int32_t native_mask = 1 << (SharedFunctionInfo::kNative + kSmiTagSize);
-      __ And(at, a4, Operand(strict_mode_function_mask | native_mask));
+      __ And(at, t0, Operand(strict_mode_function_mask | native_mask));
       __ Branch(&cont, ne, at, Operand(zero_reg));
     }
 
@@ -3271,8 +3271,8 @@ void CallFunctionStub::Generate(MacroAssembler* masm) {
 
     if (NeedsChecks()) {
       __ JumpIfSmi(a3, &wrap);
-      __ GetObjectType(a3, a4, a4);
-      __ Branch(&wrap, lt, a4, Operand(FIRST_SPEC_OBJECT_TYPE));
+      __ GetObjectType(a3, t0, t0);
+      __ Branch(&wrap, lt, t0, Operand(FIRST_SPEC_OBJECT_TYPE));
     } else {
       __ jmp(&wrap);
     }