Introduce a class to carry around a deoptimization reason.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 11b170b73818ab61ea2317107525b1ede4a64490..300572a740d0665d23beead0f0193825c54891c9 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -342,7 +342,7 @@ bool LCodeGen::GenerateJumpTable() {
       int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
       DCHECK_NE(Deoptimizer::kNotDeoptimizationEntry, id);
       Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
-      DeoptComment(table_entry->mnemonic, table_entry->reason);
+      DeoptComment(table_entry->reason);
 
       // Second-level deopt table entries are contiguous and small, so instead
       // of loading the full, absolute address of each one, load an immediate
@@ -846,7 +846,7 @@ void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
 
 
 void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
-                            const char* reason,
+                            const char* detail,
                             Deoptimizer::BailoutType bailout_type) {
   LEnvironment* environment = instr->environment();
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
@@ -899,12 +899,13 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
     __ stop("trap_on_deopt", condition);
   }
 
+  Deoptimizer::Reason reason(instr->Mnemonic(), detail);
   DCHECK(info()->IsStub() || frame_is_built_);
   // Go through jump table if we need to handle condition, build frame, or
   // restore caller doubles.
   if (condition == al && frame_is_built_ &&
       !info()->saves_caller_doubles()) {
-    DeoptComment(instr->Mnemonic(), reason);
+    DeoptComment(reason);
     __ Call(entry, RelocInfo::RUNTIME_ENTRY);
   } else {
     // We often have several deopts to the same entry, reuse the last
@@ -913,8 +914,8 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
         (deopt_jump_table_.last().address != entry) ||
         (deopt_jump_table_.last().bailout_type != bailout_type) ||
         (deopt_jump_table_.last().needs_frame != !frame_is_built_)) {
-      Deoptimizer::JumpTableEntry table_entry(entry, instr->Mnemonic(), reason,
-                                              bailout_type, !frame_is_built_);
+      Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
+                                              !frame_is_built_);
       deopt_jump_table_.Add(table_entry, zone());
     }
     __ b(condition, &deopt_jump_table_.last().label);
@@ -923,11 +924,11 @@ void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
 
 
 void LCodeGen::DeoptimizeIf(Condition condition, LInstruction* instr,
-                            const char* reason) {
+                            const char* detail) {
   Deoptimizer::BailoutType bailout_type = info()->IsStub()
       ? Deoptimizer::LAZY
       : Deoptimizer::EAGER;
-  DeoptimizeIf(condition, instr, reason, bailout_type);
+  DeoptimizeIf(condition, instr, detail, bailout_type);
 }