gdb/testsuite: add a clang XFAIL to gdb.python/py-watchpoint.exp

Clang doesn't use CFA information for variable locations. This makes it
so software breakpoints get a false hit when rbp gets popped, causing
a FAIL in gdb.python/py-watchpoint.exp. Since this is nothing wrong with
GDB itself, add an xfail to reduce noise.

Approved-By: Tom Tromey <tom@tromey.com>
1 file changed