AOSP: Use '-Os' rather than '-Oz' Cuttlefish recently hit a clang compiler issue related to -Oz: b/200617543 This is fixed by either disabling optimizations for ScopedExit or using -Os. This CL will switch ANGLE to using -Os. When building CF in AOSP, the binary size is reduced with -Os vs -Oz: -Oz: 16,383,489 bytes -Os: 16,152,509 bytes Bug: b/200617543 Change-Id: Ic920b0e0e4a61453d9657101a4560f74d90d5744 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3253128 Reviewed-by: Jason Macnak <natsu@google.com> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Tim Van Patten <timvp@google.com>