[binutils-gdb] Allow - in %p for printf

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT b8c2339b2f46d4885b933b832fc5b37c7ca101a6 ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: b8c2339b2f46d4885b933b832fc5b37c7ca101a6

Allow - in %p for printf

PR cli/19918 points out that a printf format like "%-5p" will cause a
gdb crash.  The bug is problem is that printf_pointer doesn't take the
"-" flag into account.

gdb/ChangeLog
2018-03-14  Tom Tromey  <tom@tromey.com>

	PR cli/19918:
	* printcmd.c (printf_pointer): Allow "-" in format.

gdb/testsuite/ChangeLog
2018-03-14  Tom Tromey  <tom@tromey.com>

	PR cli/19918:
	* gdb.base/printcmds.exp (test_printf): Add printf test using '-'
	flag.