MIPS: Add negative lookups to polymorphic loads in Crankshaft.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 14b73082fc8038bb7ebd38920f5de0d41ce799d8..51b3a3823f6082cb41c8383dafb60afc73fb80b8 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3473,6 +3473,16 @@ void MacroAssembler::CompareMapAndBranch(Register obj,
                                          Label* branch_to,
                                          CompareMapMode mode) {
   lw(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
+  CompareMapAndBranch(scratch, map, early_success, cond, branch_to, mode);
+}
+
+
+void MacroAssembler::CompareMapAndBranch(Register obj_map,
+                                         Handle<Map> map,
+                                         Label* early_success,
+                                         Condition cond,
+                                         Label* branch_to,
+                                         CompareMapMode mode) {
   Operand right = Operand(map);
   if (mode == ALLOW_ELEMENT_TRANSITION_MAPS) {
     ElementsKind kind = map->elements_kind();
@@ -3483,13 +3493,13 @@ void MacroAssembler::CompareMapAndBranch(Register obj,
         kind = GetNextMoreGeneralFastElementsKind(kind, packed);
         current_map = current_map->LookupElementsTransitionMap(kind);
         if (!current_map) break;
-        Branch(early_success, eq, scratch, right);
+        Branch(early_success, eq, obj_map, right);
         right = Operand(Handle<Map>(current_map));
       }
     }
   }
 
-  Branch(branch_to, cond, scratch, right);
+  Branch(branch_to, cond, obj_map, right);
 }