package/atop: work around gcc bug 85180

With Microblaze Gcc version < 8.x the build hangs due to gcc bug
85180: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180. The bug
shows up when building atop 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/94aa00f776b8a3491ac0b3212c95f5e666c5a29a/

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

package/atop/atop.mk

@@ -10,8 +10,15 @@ ATOP_LICENSE = GPL-2.0+
 ATOP_LICENSE_FILES = COPYING
 ATOP_DEPENDENCIES = ncurses zlib
 
+ATOP_CFLAGS = $(TARGET_CFLAGS)
+
+ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_85180),y)
+ATOP_CFLAGS += -O0
+endif
+
 define ATOP_BUILD_CMDS
-	$(MAKE) $(TARGET_CONFIGURE_OPTS) -C $(@D)
+	$(MAKE) $(TARGET_CONFIGURE_OPTS) CFLAGS="$(ATOP_CFLAGS)" \
+		-C $(@D)
 endef
 
 define ATOP_INSTALL_TARGET_CMDS