GCC 4.9.1 on OSX 10.10

➜  gcc-4.8.3  ./configure --enable-plugin
[...]
➜  gcc-4.8.3  make
[ -f stage_final ] || echo stage3 > stage_final
mkdir host-x86_64-apple-darwin14.0.0
Configuring stage 1 in host-x86_64-apple-darwin14.0.0/intl
configure: creating cache ./config.cache
checking whether /Applications/Xcode.app/Contents/Developer/usr/bin/make sets $(MAKE)... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether NLS is requested... yes
checking for msgfmt... no
checking for gmsgfmt... :
checking for xgettext... no
[...]
libtool: compile:  /Users/Max13/gcc-4.8.3/host-x86_64-apple-darwin14.0.0/gcc/xgcc -shared-libgcc -B/Users/Max13/gcc-4.8.3/host-x86_64-apple-darwin14.0.0/gcc -nostdinc++ -L/Users/Max13/gcc-4.8.3/x86_64-apple-darwin14.0.0/i386/libstdc++-v3/src -L/Users/Max13/gcc-4.8.3/x86_64-apple-darwin14.0.0/i386/libstdc++-v3/src/.libs -B/usr/local/x86_64-apple-darwin14.0.0/bin/ -B/usr/local/x86_64-apple-darwin14.0.0/lib/ -isystem /usr/local/x86_64-apple-darwin14.0.0/include -isystem /usr/local/x86_64-apple-darwin14.0.0/sys-include -m32 -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -DASAN_HAS_EXCEPTIONS=1 -DASAN_FLEXIBLE_MAPPING_AND_OFFSET=0 -DASAN_NEEDS_SEGV=1 -DMAC_INTERPOSE_FUNCTIONS -DMISSING_BLOCKS_SUPPORT -I. -I../../../.././libsanitizer/asan -I ../../../.././libsanitizer/include -I ../../../.././libsanitizer -Wall -W -Wno-unused-parameter -Wwrite-strings -pedantic -Wno-long-long -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fvisibility=hidden -Wno-variadic-macros -I../../libstdc++-v3/include -I../../libstdc++-v3/include/x86_64-apple-darwin14.0.0 -I../../../.././libsanitizer/../libstdc++-v3/libsupc++ -g -O2 -m32 -MT asan_mac.lo -MD -MP -MF .deps/asan_mac.Tpo -c ../../../.././libsanitizer/asan/asan_mac.cc  -fno-common -DPIC -o .libs/asan_mac.o
xgcc: warning: couldn’t understand kern.osversion ‘14.0.0
../../../.././libsanitizer/asan/asan_mac.cc: In function ‘void __asan::GetPcSpBp(void*, __sanitizer::uptr*, __sanitizer::uptr*, __sanitizer::uptr*)’:
../../../.././libsanitizer/asan/asan_mac.cc:47:32: error: ‘struct mcontext32’ has no member named ‘__ss’
   *pc = ucontext->uc_mcontext->__ss.__eip;
                                ^
../../../.././libsanitizer/asan/asan_mac.cc:48:32: error: ‘struct mcontext32’ has no member named ‘__ss’
   *bp = ucontext->uc_mcontext->__ss.__ebp;
                                ^
../../../.././libsanitizer/asan/asan_mac.cc:49:32: error: ‘struct mcontext32’ has no member named ‘__ss’
   *sp = ucontext->uc_mcontext->__ss.__esp;
                                ^
../../../.././libsanitizer/asan/asan_mac.cc: At global scope:
../../../.././libsanitizer/asan/asan_mac.cc:308:6: warning: always_inline function might not be inlinable [-Wattributes]
 void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
      ^
make[7]: *** [asan_mac.lo] Error 1
make[6]: *** [all-recursive] Error 1
make[5]: *** [multi-do] Error 1
make[4]: *** [all-multi] Error 2
make[3]: *** [all-recursive] Error 1
make[2]: *** [all-stage1-target-libsanitizer] Error 2
make[1]: *** [stage1-bubble] Error 2
make: *** [all] Error 2