Introduce a class to carry around a deoptimization reason.

src/x87/lithium-codegen-x87.h

Index: src/x87/lithium-codegen-x87.h
diff --git a/src/x87/lithium-codegen-x87.h b/src/x87/lithium-codegen-x87.h
index 88d28105730ca603e688b8965f1034fdd0881143..1a4ca29a0cd150f2b900e28a62a2091efd86de2f 100644
--- a/src/x87/lithium-codegen-x87.h
+++ b/src/x87/lithium-codegen-x87.h
@@ -236,10 +236,10 @@ class LCodeGen: public LCodeGenBase {
 
   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                             Safepoint::DeoptMode mode);
-  void DeoptimizeIf(Condition cc, LInstruction* instr, const char* reason,
+  void DeoptimizeIf(Condition cc, LInstruction* instr, const char* detail,
                     Deoptimizer::BailoutType bailout_type);
   void DeoptimizeIf(Condition cc, LInstruction* instr,
-                    const char* reason = NULL);
+                    const char* detail = NULL);
 
   bool DeoptEveryNTimes() {
     return FLAG_deopt_every_n_times != 0 && !info()->IsStub();