the return type of the intrinsic is not overloaded, i.e., where the type
being matched is some other parameter.  The argument to LLVMMatchType is
an index into the list of overloaded types (ignoring the fixed types),
but VerifyIntrinsicPrototype is expecting its arguments for LLVMMatchType
parameters to be indices into the combined list of _all_ return values and
parameters, not just the overloaded ones.

This patch changes TableGen to keep track for each overloaded type of the
corresponding index into the list of return values and parameters.  It
then generates the values expected by VerifyIntrinsicPrototype.

llvm-svn: 77467