[turbofan] Remove bogus constant materialization from frame.

src/compiler/mips/code-generator-mips.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/osr.h"
@@ skipping 1992 matching lines @@
           break;
         case Constant::kFloat64:
           __ li(dst, isolate()->factory()->NewNumber(src.ToFloat64(), TENURED));
           break;
         case Constant::kExternalReference:
           __ li(dst, Operand(src.ToExternalReference()));
           break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           Heap::RootListIndex index;
-          int slot;
-          if (IsMaterializableFromFrame(src_object, &slot)) {
-            __ lw(dst, g.SlotToMemOperand(slot));
-          } else if (IsMaterializableFromRoot(src_object, &index)) {
+          if (IsMaterializableFromRoot(src_object, &index)) {
             __ LoadRoot(dst, index);
           } else {
             __ li(dst, src_object);
           }
           break;
         }
         case Constant::kRpoNumber:
           UNREACHABLE();  // TODO(titzer): loading RPO numbers on mips.
           break;
       }
@@ skipping 182 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8