Added the xlc-* and mpcc_r-* BASENAME patterns to be recognized as IBM
compilers so that the ibm compiler options can be added properly.
This allows non-system-default compiler command names (e.g. xlc-m.n.k.l)
be recognized.
(need to figure out a better way to recognize it is an IBM compiler
and its version information.)
Tested: LLNL AIX machine.