[MemoryLocation] Support memcpy_chk in getForArgument.

Similar to 9f9e8ba1, add support for memcyp_chk to
MemoryLocation::getForArgument.

The size argument for memcpy_chk is an upper bound for the size of the
pointer argument. memcpy_chk may read/write less than the specified length,
if it exceeds the specified max size and aborts.

Reviewed By: xbolva00, jdoerfert

Differential Revision: https://reviews.llvm.org/D138613