A64: Rejig truncating and non double to i/smi

src/a64/macro-assembler-a64.h

Index: src/a64/macro-assembler-a64.h
diff --git a/src/a64/macro-assembler-a64.h b/src/a64/macro-assembler-a64.h
index 8b8783c284e1dae95736b2bc88918a1f6986fa04..9c04d214aea7c489ff150890f5361b277b5d43f4 100644
--- a/src/a64/macro-assembler-a64.h
+++ b/src/a64/macro-assembler-a64.h
@@ -789,6 +789,9 @@ class MacroAssembler : public Assembler {
                            Label* on_not_heap_number,
                            Register heap_number_map = NoReg);
 
+  // Jump to label if the input double register contains -0.0.
+  void JumpIfMinusZero(DoubleRegister input, Label* on_negative_zero);
+
   // Saturate a signed 32-bit integer in input to an unsigned 8-bit integer in
   // output.
   void ClampInt32ToUint8(Register in_out);