Extract hardcoded error strings into a single place and replace them with enum.

src/ia32/codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 761 matching lines @@
     __ pop(ebx);
     __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
   }
   __ jmp(&entry);
 
   // Found hole, store hole_nan_as_double instead.
   __ bind(&convert_hole);
 
   if (FLAG_debug_code) {
     __ cmp(ebx, masm->isolate()->factory()->the_hole_value());
-    __ Assert(equal, "object found in smi-only array");
+    __ Assert(equal, kObjectFoundInSmiOnlyArray);
   }
 
   if (CpuFeatures::IsSupported(SSE2)) {
     CpuFeatureScope use_sse2(masm, SSE2);
     __ movdbl(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize),
               the_hole_nan);
   } else {
     __ fld_d(Operand::StaticVariable(canonical_the_hole_nan_reference));
     __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
   }
@@ skipping 211 matching lines @@
   STATIC_ASSERT(kSeqStringTag == 0);
   __ test(result, Immediate(kStringRepresentationMask));
   __ j(zero, &seq_string, Label::kNear);
 
   // Handle external strings.
   Label ascii_external, done;
   if (FLAG_debug_code) {
     // Assert that we do not have a cons or slice (indirect strings) here.
     // Sequential strings have already been ruled out.
     __ test(result, Immediate(kIsIndirectStringMask));
-    __ Assert(zero, "external string expected, but not found");
+    __ Assert(zero, kExternalStringExpectedButNotFound);
   }
   // Rule out short external strings.
   STATIC_CHECK(kShortExternalStringTag != 0);
   __ test_b(result, kShortExternalStringMask);
   __ j(not_zero, call_runtime);
   // Check encoding.
   STATIC_ASSERT(kTwoByteStringTag == 0);
   __ test_b(result, kStringEncodingMask);
   __ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
   __ j(not_equal, &ascii_external, Label::kNear);
@@ skipping 147 matching lines @@
     Code* stub = GetCodeAgeStub(age, parity);
     CodePatcher patcher(sequence, young_length);
     patcher.masm()->call(stub->instruction_start(), RelocInfo::NONE32);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32