MinGW does not have _ReadWriteBarrier() intrinsic, but does have GCC inline assembler, so use the GCC definitions instead of MSVC ones.
Created attachment 212135 [details] Patch
Comment on attachment 212135 [details] Patch Clearing flags on attachment: 212135 Committed r156170: <http://trac.webkit.org/changeset/156170>
All reviewed patches have been landed. Closing bug.