package/ace: fix build failure due to gcc bug 101915

The ace package exhibits gcc bug 101915 when built for the Microblaze
architecture with optimization enabled, which causes a build failure.

As done for other packages in Buildroot work around this gcc bug by
setting optimization to -O0 if BR2_TOOLCHAIN_HAS_GCC_BUG_101915=y.

Fixes:
http://autobuild.buildroot.net/results/f8f/f8f8de99abe92175954c370ad99fee43942bcdcc/

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
[yann.morin.1998@free.fr: slight simplification]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 803247337d35643afdca9718c4616500b9930f2d)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ace/ace.mk

@@ -17,9 +17,15 @@ ACE_CPE_ID_PRODUCT = adaptive_communication_environment
 # Only compiling ACE libraries (no TAO)
 ACE_LIBARIES = ace ACEXML Kokyu netsvcs protocols/ace
 
+ACE_CPPFLAGS = $(TARGET_CPPFLAGS) -std=c++11
+
+ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_101915),y)
+ACE_CPPFLAGS += -O0
+endif
+
 ACE_MAKE_OPTS = \
 	ACE_ROOT="$(@D)" \
-	DEFFLAGS="$(TARGET_CPPFLAGS) -std=c++11"
+	DEFFLAGS="$(ACE_CPPFLAGS)"
 
 ifeq ($(BR2_PACKAGE_OPENSSL),y)
 ACE_LIBARIES += ace/SSL