MIPS: Reland 10216 - Optimize the equality check case of ICCompare stubs.

src/mips/ic-mips.cc

Index: src/mips/ic-mips.cc
diff --git a/src/mips/ic-mips.cc b/src/mips/ic-mips.cc
index b057695f0105b9b19ea9e6a10398399c2e047b21..c240125bba1b0f745efb7f4c6b7a48d5627620f9 100644
--- a/src/mips/ic-mips.cc
+++ b/src/mips/ic-mips.cc
@@ -1587,6 +1587,9 @@ void CompareIC::UpdateCaches(Handle<Object> x, Handle<Object> y) {
     rewritten = stub.GetCode();
   } else {
     ICCompareStub stub(op_, state);
+    if (state == KNOWN_OBJECTS) {
+      stub.set_known_map(Handle<Map>(Handle<JSObject>::cast(x)->map()));
+    }
     rewritten = stub.GetCode();
   }
   set_target(*rewritten);