Remove the compiled_transitions flag and cleanup the unused code.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index ba954017a7736dcb85bc2a47885581ff375ae9e9..6bd45fe2f2353633032609927c205d0e483fa763 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4455,7 +4455,7 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
     // Write barrier.
     __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                         scratch, GetRAState(), kDontSaveFPRegs);
-  } else if (FLAG_compiled_transitions) {
+  } else {
     PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
     __ mov(a0, object_reg);
     __ li(a1, Operand(to_map));
@@ -4463,28 +4463,6 @@ 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(a2));
-    Register new_map_reg = ToRegister(instr->new_map_temp());
-    ASSERT(new_map_reg.is(a3));
-    __ li(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(a2));
-    Register new_map_reg = ToRegister(instr->new_map_temp());
-    ASSERT(new_map_reg.is(a3));
-    __ li(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);
 }