Vulkan: Use VK_EXT_primitives_generated_query This Vulkan extension implements OpenGL's primitives generated query. The heavy lifting in ANGLE's implementation was done when this query was emulated with pipeline statistics query. This change simply switches pipeline statistics query usage to this dedicated query when available. Bug: angleproject:5430 Change-Id: I5d2c7d64e4627bcbd33d428d6a7c836b1129e5fd Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3813815 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Ian Elliott <ianelliott@google.com> Commit-Queue: Yuxin Hu <yuxinhu@google.com>