Extends testb and cmpb/cmpw instruction support in the ia32 assembler.

src/regexp/ia32/regexp-macro-assembler-ia32.cc

Index: src/regexp/ia32/regexp-macro-assembler-ia32.cc
diff --git a/src/regexp/ia32/regexp-macro-assembler-ia32.cc b/src/regexp/ia32/regexp-macro-assembler-ia32.cc
index 5191a290a4dfb154f24f61112300058109749a79..9c55af6645b1b507ba239099c20caf36abda3f4b 100644
--- a/src/regexp/ia32/regexp-macro-assembler-ia32.cc
+++ b/src/regexp/ia32/regexp-macro-assembler-ia32.cc
@@ -511,7 +511,8 @@ void RegExpMacroAssemblerIA32::CheckBitInTable(
     __ and_(ebx, current_character());
     index = ebx;
   }
-  __ cmpb(FieldOperand(eax, index, times_1, ByteArray::kHeaderSize), 0);
+  __ cmpb(FieldOperand(eax, index, times_1, ByteArray::kHeaderSize),
+          Immediate(0));
   BranchOrBacktrack(not_equal, on_bit_set);
 }