package/libtorrent-rasterbar: work around gcc bug 85180

package/libtorrent-rasterbar: work around gcc bug 85180

On Microblaze, building libtorrent-rasterbar with gcc version < 8.x
and optimization enabled causes gcc to enter an infinite loop and
hangs the build.

This is due to gcc bug 85180
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180).

The bug shows up when building libtorrent-rasterbar with optimization
but not when building with -O0. To work around this, if
BR2_TOOLCHAIN_HAS_GCC_BUG_85180=y we force using -O0.

Fixes:
http://autobuild.buildroot.net/results/410/410e75676abc6bbabe9029ecda969e3d909f3e18/

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>