qemu not building on -current with gcc

[Thomas Klausner <wiz%NetBSD.org@localhost>]

qemu is not building for me on NetBSD-6.99.40 with gcc-4.8.

The error is (after I turn off parallel building with MAKE_JOBS_SAFE=no):

  LINK  aarch64-softmmu/qemu-system-aarch64
/usr/lib/libc.so: warning: multiple common of `environ'
/usr/lib/crt0.o: warning: previous common is here
target-arm/helper-a64.o: In function `clrsb64':
/scratch/emulators/qemu/work/qemu-2.0.0/include/qemu/host-utils.h:284: 
undefined reference to `__clrsbdi2'
target-arm/helper-a64.o: In function `clrsb32':
/scratch/emulators/qemu/work/qemu-2.0.0/include/qemu/host-utils.h:268: 
undefined reference to `__clrsbdi2'
Makefile:173: recipe for target 'qemu-system-aarch64' failed
make[1]: *** [qemu-system-aarch64] Error 1
Makefile:167: recipe for target 'subdir-aarch64-softmmu' failed
gmake: *** [subdir-aarch64-softmmu] Error 2
*** Error code 2

I heard that it builds with clang on NetBSD-current.

Has anyone else tried with gcc?
Any ideas about the fix?
 Thomas