implement more checking to reject things like:

implement more checking to reject things like:
  (someinst GR16:$foo, GR32:$foo)

Reimplement BuildAliasOperandReference to be correctly
based on the names of operands in the result pattern,
instead of on the instruction operand definitions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118328 91177308-0d34-0410-b5e6-96231b3b80d8