There are some Mips instructions that are lowered by the

There are some Mips instructions that are lowered by the
assembler such as shifts greater than 32. In the case
of direct object, the code gen needs to do this lowering
since the assembler is not involved.

With the advent of the llvm-mc assembler, it also needs
to do the same lowering.

This patch makes that specific lowering code accessible
to both the direct object output and the assembler.

This patch does not affect generated output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163287 91177308-0d34-0410-b5e6-96231b3b80d8