X87: Made the detailed reason for deopts mandatory on x87. Unified and improved things.

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 1a4ca29a0cd150f2b900e28a62a2091efd86de2f..2f4a8d3111d96c3190431198ebdcd2a23e7a5ed8 100644
--- a/src/x87/lithium-codegen-x87.h
+++ b/src/x87/lithium-codegen-x87.h
@@ -238,8 +238,7 @@ class LCodeGen: public LCodeGenBase {
                                             Safepoint::DeoptMode mode);
   void DeoptimizeIf(Condition cc, LInstruction* instr, const char* detail,
                     Deoptimizer::BailoutType bailout_type);
-  void DeoptimizeIf(Condition cc, LInstruction* instr,
-                    const char* detail = NULL);
+  void DeoptimizeIf(Condition cc, LInstruction* instr, const char* detail);
 
   bool DeoptEveryNTimes() {
     return FLAG_deopt_every_n_times != 0 && !info()->IsStub();