[stubs] Split ToNumberStub into reusable subparts.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index d5b4d5955deec61ebf2ef5fa05281e59305b9fcd..1bd9fe3d20e0849516fbca59ce27a097cba35d61 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -5320,6 +5320,15 @@ void MacroAssembler::JumpIfEitherSmi(Register reg1,
   JumpIfSmi(at, on_either_smi);
 }
 
+void MacroAssembler::AssertNotNumber(Register object) {
+  if (emit_debug_code()) {
+    STATIC_ASSERT(kSmiTag == 0);
+    andi(at, object, kSmiTagMask);
+    Check(ne, kOperandIsANumber, at, Operand(zero_reg));
+    GetObjectType(object, t8, t8);
+    Check(ne, kOperandIsNotANumber, t8, Operand(HEAP_NUMBER_TYPE));
+  }
+}
 
 void MacroAssembler::AssertNotSmi(Register object) {
   if (emit_debug_code()) {