Renamed gdb.t*/in-gdbme* to gdb.t*/gdbme*. Changed to use CC, CXX
instead of CC_FOR_TARGET, CXX_FOR_TARGET. Added mostlyclean and
distclean targets. Built executables via .o files. Adjusted
tests to account for source files in $(srcdir) rather than
$(objdir).
* lib/gdb.exp (runto): Don't expect () after the function name,
because it may have arguments.