This is the second minimal patch keeping Nios2 target buildable.
I'm adding subtarget here and other stuff for frame lowering, instruction,
register information methods. I do not add any test cases, as still there
are missing parts like DAG selector and assembly printing. I plan to include
them into the next patch.
Patch by Andrei Grischenko <andrei.l.grischenko@intel.com>
Differential Revision: https://reviews.llvm.org/D37256
llvm-svn: 313626