Add target flags to SPARC address operands.

SDNodes and MachineOperands get target flags representing the %hi() and
%lo() assembly annotations that eventually become relocations.

Also define flags to be used by the 64-bit code models.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179468 91177308-0d34-0410-b5e6-96231b3b80d8