Upgrade V8 to 5.1.281.57

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
diff --git a/src/regexp/x87/regexp-macro-assembler-x87.cc b/src/regexp/x87/regexp-macro-assembler-x87.cc
index 6e62092..9f15b1c 100644
--- a/src/regexp/x87/regexp-macro-assembler-x87.cc
+++ b/src/regexp/x87/regexp-macro-assembler-x87.cc
@@ -510,7 +510,8 @@
     __ 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);
 }
 
@@ -935,7 +936,8 @@
       isolate()->factory()->NewCode(code_desc,
                                     Code::ComputeFlags(Code::REGEXP),
                                     masm_->CodeObject());
-  PROFILE(isolate(), RegExpCodeCreateEvent(*code, *source));
+  PROFILE(masm_->isolate(),
+          RegExpCodeCreateEvent(AbstractCode::cast(*code), *source));
   return Handle<HeapObject>::cast(code);
 }