Add missing EXPORT qualifier
Merge branch 'master' of https://github.com/Halide/halide
Fix race condition for C++ < C++11

Was crashing simd_op_check occasionally.

I'm a little suprised that Halide isn't thread-unsafe elsewhere
(e.g. unique_name, shared pointer reference counts) but I guess
if you never pass an Expr, Func, etc across threads, it all works.
Windows build fix
Fix for trunk llvm
Merge branch 'master' into ucon-target
Minor linux build fix.