[testsuite/guality] Run guality tests with Og

[testsuite/guality] Run guality tests with Og

We advertise Og as the optimization level of choice for the standard
edit-compile-debug cycle, but do not run the guality tests for Og with the
default torture options.

This patch ensures that we test -Og in the guality tests.

F.i., for gcc.dg/guality there are 45 fails for Og (while there are none for
O1), in these test-cases:
...
gcc.dg/guality/pr54200.c
gcc.dg/guality/pr54970.c
gcc.dg/guality/pr56154-1.c
gcc.dg/guality/pr59776.c
gcc.dg/guality/sra-1.c
...

2018-07-15  Tom de Vries  <tdevries@suse.de>

	* lib/gcc-gdb-test.exp (guality_minimal_options): New proc.
	* g++.dg/guality/guality.exp: Ensure Og is part of torture options.
	* gcc.dg/guality/guality.exp: Same.
	* gfortran.dg/guality/guality.exp: Same.

From-SVN: r262666