MIPS: [turbofan] Optimize fpu compares with zero literal.

src/mips64/macro-assembler-mips64.h

Index: src/mips64/macro-assembler-mips64.h
diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index 2edc82950d16e3fb12fa078d565724ecde38dda6..a4ecae49d6a263fd47cd2e859f952ee525af0968 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -1719,6 +1719,8 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
   void JumpIfDictionaryInPrototypeChain(Register object, Register scratch0,
                                         Register scratch1, Label* found);
 
+  bool IsDoubleZeroRegSet() { return has_double_zero_reg_set_; }
+
  private:
   void CallCFunctionHelper(Register function,
                            int num_reg_arguments,