-p as an alias for -pg?

So it isn't clear if -p should be an alias of -pg everywhere
or if it should be target specific. With gcc on OpenBSD
-p and -pg are the same. But it seems on sysv unices,
-p is for prof/mon.out instead of gprof/gmon.out formats,
or was historically.

It isn't entirely obvious how to add an alias after the
command is already added via TableGen. So if the following
isn't the way to go can someone give hints on how to
do it in a way that is target specific?

Index: include/clang/Driver/Options.td

The gcc manual still says they are different, but in a small test they
produced identical output.

I think your proposed patch is OK. If someone finds a need to
differentiate -p and -pg we can implement that later.


Is there any reason this couldn't be committed?