[Object][Mips] Return address of MIPS symbol with cleared microMIPS indicator bit

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222726 91177308-0d34-0410-b5e6-96231b3b80d8
Fix overly aggressive type merging.

If we find out that two types are *not* isomorphic, we learn nothing about
opaque sub types in both the source and destination.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222727 91177308-0d34-0410-b5e6-96231b3b80d8