Remove the compiled_transitions flag and cleanup the unused code.

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 ff1c33bf5cfbd953c6ef2532f25360609ebce236..057ca1ef2bae528deba94161f7478d26203a4d8c 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4507,7 +4507,7 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
     // Write barrier.
     __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                         scratch, GetLinkRegisterState(), kDontSaveFPRegs);
-  } else if (FLAG_compiled_transitions) {
+  } else {
     PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
     __ Move(r0, object_reg);
     __ Move(r1, to_map);
@@ -4515,28 +4515,6 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
     __ CallStub(&stub);
     RecordSafepointWithRegisters(
         instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
-  } else if (IsFastSmiElementsKind(from_kind) &&
-             IsFastDoubleElementsKind(to_kind)) {
-    Register fixed_object_reg = ToRegister(instr->temp());
-    ASSERT(fixed_object_reg.is(r2));
-    Register new_map_reg = ToRegister(instr->new_map_temp());
-    ASSERT(new_map_reg.is(r3));
-    __ mov(new_map_reg, Operand(to_map));
-    __ mov(fixed_object_reg, object_reg);
-    CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
-             RelocInfo::CODE_TARGET, instr);
-  } else if (IsFastDoubleElementsKind(from_kind) &&
-             IsFastObjectElementsKind(to_kind)) {
-    Register fixed_object_reg = ToRegister(instr->temp());
-    ASSERT(fixed_object_reg.is(r2));
-    Register new_map_reg = ToRegister(instr->new_map_temp());
-    ASSERT(new_map_reg.is(r3));
-    __ mov(new_map_reg, Operand(to_map));
-    __ mov(fixed_object_reg, object_reg);
-    CallCode(isolate()->builtins()->TransitionElementsDoubleToObject(),
-             RelocInfo::CODE_TARGET, instr);
-  } else {
-    UNREACHABLE();
   }
   __ bind(&not_applicable);
 }