Optimizing: Create fewer handles in inliner.

Use ObjPtr<> and bool instead of ReferenceTypeInfo to avoid
creating unnecessary temporary Handle<>s. This should reduce
compiler memory use a little bit.

And rewrite ReferenceTypePropagation::IsAdmissible() with
an explicit loop instead of a tail recursion.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boots.
Change-Id: Ic9952134d669b336fb28e6ea13117446d11dc145
4 files changed