For PR1297:

Implement bswap, ctpop, ctlz, and cttz utilizing the new overloaded
intrinsic feature of tblgen. By defining llvm_int_ty to have an ValueType
of iAny, any intrinsic using that type becomes an overloaded intrinsic.
This signals that a) any integer type could be used for that argument and
b) the intrinsic needs a suffix to match each such argument for the
actual intrinsic.

llvm-svn: 35544