Turn CHECK()s into ASSERT()s.

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 bdbc010bd3840ae5715986e7b9055bde909a20a2..95ee3a6c12dd2c2b1ced217c8b2193372775a5ee 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -1732,9 +1732,10 @@ void LCodeGen::DoConstantT(LConstantT* instr) {
   AllowDeferredHandleDereference smi_check;
   if (instr->hydrogen()->HasObjectMap()) {
     Handle<Map> object_map = instr->hydrogen()->ObjectMap().handle();
-    CHECK(object->IsHeapObject());
-    CHECK(!object_map->is_stable() ||
-          *object_map == Handle<HeapObject>::cast(object)->map());
+    ASSERT(object->IsHeapObject());
+    ASSERT(!object_map->is_stable() ||
+           *object_map == Handle<HeapObject>::cast(object)->map());
+    USE(object_map);
   }
   __ li(ToRegister(instr->result()), object);
 }