[yann@localhost build]$ make ENABLE_OPTIMIZED=1 -j1
make[1]: Entering directory '/home/yann/dev/llvm-or1k/build/lib/Support'
llvm[1]: Compiling APFloat.cpp for Release+Asserts build
In file included from /home/yann/dev/llvm-or1k/lib/Support/APFloat.cpp:16:
In file included from /home/yann/dev/llvm-or1k/include/llvm/ADT/APFloat.h:20:
In file included from /home/yann/dev/llvm-or1k/include/llvm/ADT/APInt.h:19:
In file included from /home/yann/dev/llvm-or1k/include/llvm/ADT/ArrayRef.h:14:
In file included from /home/yann/dev/llvm-or1k/include/llvm/ADT/SmallVector.h:18:
In file included from /home/yann/dev/llvm-or1k/include/llvm/Support/AlignOf.h:19:
/usr/lib/gcc/x86_64-redhat-linux/4.9.2/../../../../include/c++/4.9.2/cstddef:51:11: error: no member named 'max_align_t' in the global namespace
  using ::max_align_t;
        ~~^
1 error generated.
/home/yann/dev/llvm-or1k/Makefile.rules:1509: recipe for target '/home/yann/dev/llvm-or1k/build/lib/Support/Release+Asserts/APFloat.o' failed
make[1]: *** [/home/yann/dev/llvm-or1k/build/lib/Support/Release+Asserts/APFloat.o] Error 1
make[1]: Leaving directory '/home/yann/dev/llvm-or1k/build/lib/Support'
/home/yann/dev/llvm-or1k/Makefile.rules:877: recipe for target 'all' failed
make: *** [all] Error 1