Implement build option for load-time GlobalMutex allocation. Performance difference on S906B for 1000'000 `eglGetError()` calls. Before: 26.5 ms After: 23.8 ms (Assuming `angle::FastMutex2` is used). Potentially can be enabled for other platforms. Bug: angleproject:8101 Change-Id: Ic2037edaae6da82dbded71288bae250d7981e7d3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4386408 Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Igor Nazarov <i.nazarov@samsung.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>