[cfe-dev] can't build svn clang under fresh ubuntu 14.04 x64/gcc4.9.2

[Dennis Luehring]

i've followed the clang build-instructions on 
http://clang.llvm.org/get_started.html

on an recent ubuntu 14.04 x64 + gcc 4.9.2

using
llvm svn 228148
clang svn 228148
compiler-rt svn 228148

svn co + configures worked

make failed with
-------------------------
test at ubuntu:~/build$ make
llvm[0]: Constructing LLVMBuild project information.
make[1]: Entering directory `/home/test/build/lib/Support'
llvm[1]: Compiling APFloat.cpp for Debug+Asserts build
In file included from /home/test/llvm/lib/Support/APFloat.cpp:15:
In file included from /home/test/llvm/include/llvm/ADT/APFloat.h:20:
In file included from /home/test/llvm/include/llvm/ADT/APInt.h:19:
In file included from /home/test/llvm/include/llvm/ADT/ArrayRef.h:14:
In file included from /home/test/llvm/include/llvm/ADT/STLExtras.h:21:
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/cstddef:51:11: 
error:
       no member named 'max_align_t' in the global namespace
   using ::max_align_t;
         ~~^
1 error generated.
make[1]: *** [/home/test/build/lib/Support/Debug+Asserts/APFloat.o] Error 1
make[1]: Leaving directory `/home/test/build/lib/Support'
make: *** [all] Error 1
-------------------------

my gcc -v
-------------------------
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 
4.9.2-0ubuntu1~14.04' 
--with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs 
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr 
--program-suffix=-4.9 --enable-shared --enable-linker-build-id 
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix 
--with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib 
--enable-nls --with-sysroot=/ --enable-clocale=gnu 
--enable-libstdcxx-debug --enable-libstdcxx-time=yes 
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin 
--with-system-zlib --disable-browser-plugin --enable-java-awt=gtk 
--enable-gtk-cairo 
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre 
--enable-java-home 
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64 
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64 
--with-arch-directory=amd64 
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc 
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic 
--enable-checking=release --build=x86_64-linux-gnu 
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.9.2 (Ubuntu 4.9.2-0ubuntu1~14.04)
-------------------------

i've found bug reports for this error in several distrubution buglist 
but no solution - any idea?