S390: [stubs] Split ToNumberStub into reusable subparts.

src/s390/macro-assembler-s390.h

Index: src/s390/macro-assembler-s390.h
diff --git a/src/s390/macro-assembler-s390.h b/src/s390/macro-assembler-s390.h
index 5b38e30a0dfb3a53fa6c8b55cca6e14e89644818..8d4ca9014166544acd34ebc5d92e03a6cd4c4185 100644
--- a/src/s390/macro-assembler-s390.h
+++ b/src/s390/macro-assembler-s390.h
@@ -1630,6 +1630,9 @@ class MacroAssembler : public Assembler {
   // Jump if either of the registers contain a smi.
   void JumpIfEitherSmi(Register reg1, Register reg2, Label* on_either_smi);
 
+  // Abort execution if argument is a number, enabled via --debug-code.
+  void AssertNotNumber(Register object);
+
   // Abort execution if argument is a smi, enabled via --debug-code.
   void AssertNotSmi(Register object);
   void AssertSmi(Register object);