Fix handling of -0 in the unary-op IC and avoid repeated patching/transitions.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
===================================================================
--- src/arm/code-stubs-arm.cc	(revision 7936)
+++ src/arm/code-stubs-arm.cc	(working copy)
@@ -1847,12 +1847,14 @@
 
 
 void TypeRecordingUnaryOpStub::GenerateHeapNumberStubSub(MacroAssembler* masm) {
-  Label non_smi, slow;
-  GenerateSmiCodeSub(masm, &non_smi, &slow);
+  Label non_smi, slow, call_builtin;
+  GenerateSmiCodeSub(masm, &non_smi, &call_builtin);
   __ bind(&non_smi);
   GenerateHeapNumberCodeSub(masm, &slow);
   __ bind(&slow);
   GenerateTypeTransition(masm);
+  __ bind(&call_builtin);
+  GenerateGenericCodeFallback(masm);
 }