MSVC 2015 + LLVM 4.0 RC2 problem compiling LLVMPipe of Mesa 17.0

I got this error compiling LLVMPipe using LLVM 4.0 RC2:
No error using 3.9.1 (so the problem is related to 4.0 changes)
I’m using MSVC 2015.

" Compiling src\compiler\glsl\ast_array_index.cpp …
ast_array_index.cpp
c:\projects\mesa-master\include\c11\threads_win32.h(151): error C2027: use of undefined type ‘xtime’
C:\Projects\mesa-master\include\c11/threads.h(48): note: see declaration of ‘xtime’
c:\projects\mesa-master\include\c11\threads_win32.h(151): error C2227: left of ‘->sec’ must point to class/struct/union/generic type
c:\projects\mesa-master\include\c11\threads_win32.h(151): error C2227: left of ‘->nsec’ must point to class/struct/union/generic type
c:\projects\mesa-master\include\c11\threads_win32.h(446): error C2027: use of undefined type ‘xtime’
C:\Projects\mesa-master\include\c11/threads.h(48): note: see declaration of ‘xtime’
c:\projects\mesa-master\include\c11\threads_win32.h(446): error C2227: left of ‘->sec’ must point to class/struct/union/generic type
c:\projects\mesa-master\include\c11\threads_win32.h(637): error C2027: use of undefined type ‘xtime’
C:\Projects\mesa-master\include\c11/threads.h(48): note: see declaration of ‘xtime’
c:\projects\mesa-master\include\c11\threads_win32.h(637): error C2227: left of ‘->sec’ must point to class/struct/union/generic type
c:\projects\mesa-master\include\c11\threads_win32.h(638): error C2027: use of undefined type ‘xtime’
C:\Projects\mesa-master\include\c11/threads.h(48): note: see declaration of ‘xtime’
c:\projects\mesa-master\include\c11\threads_win32.h(638): error C2227: left of ‘->nsec’ must point to class/struct/union/generic type
scons: *** [build\windows-x86\gallium\auxiliary\gallivm\lp_bld_misc.obj] Error 2
scons: building terminated because of errors."

Those errors are from MSVC though, so it's unclear what LLVM has got
to do with it.