Handle overwriting valueOf on String objects correctly when adding...

src/ia32/macro-assembler-ia32.cc

Index: src/ia32/macro-assembler-ia32.cc
===================================================================
--- src/ia32/macro-assembler-ia32.cc	(revision 5232)
+++ src/ia32/macro-assembler-ia32.cc	(working copy)
@@ -373,13 +373,13 @@
 
 void MacroAssembler::AbortIfNotSmi(Register object) {
   test(object, Immediate(kSmiTagMask));
-  Assert(equal, "Operand not a smi");
+  Assert(equal, "Operand is not a smi");
 }
 
 
 void MacroAssembler::AbortIfSmi(Register object) {
   test(object, Immediate(kSmiTagMask));
-  Assert(not_equal, "Operand a smi");
+  Assert(not_equal, "Operand is a smi");
 }