I'm building the following Buildroot Custom toolchain config and
noticing a libsanitizer failure. 


../../../../libsanitizer/asan/asan_linux.cc: In function âbool
__asan::AsanInterceptsSignal(int)â:
../../../../libsanitizer/asan/asan_linux.cc:222:20: error: âSIGSEGVâ
was not declared in this scope
   return signum == SIGSEGV && common_flags()->handle_segv;
                    ^
make[6]: *** [asan_linux.lo] Error 1
make[5]: *** [all-recursive] Error 1
make[4]: *** [all] Error 2
make[3]: *** [all-target-libsanitizer] Error 2
make[2]: *** [all] Error 2
make[1]: *** [/accts/mlweber1/target/build/host-gcc-final-5.4.0/.stamp_built]
Error 2
make: *** [_all] Error 2

Config to reproduce:
BR2_powerpc=y
BR2_powerpc_e500mc=y
BR2_TOOLCHAIN_BUILDROOT_GLIBC=y
BR2_KERNEL_HEADERS_VERSION=y
BR2_DEFAULT_KERNEL_VERSION="3.12.37"
BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_3_12=y
BR2_GCC_VERSION_5_X=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_GCC_ENABLE_LTO=y

The resolution looks to be  https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg159613.html

I'll get a patch tested and I can confirm so far that the issue goes away in GCC6 but GCC5.4 has the bug.