Vulkan: Add FastIntegerSet and FastIntegerMap class Add FastIntegerSet container to enable fast contains operation for a set of integer keys. The class uses a BitSet vector to achieve performance. Add FastIntegerMap container to improve buffer serial tracking performance. FastIntegerMap uses FastIntegerSet container to track buffer serial keys. It also provides an ensureCapacity method to reserve space, for the expected buffer count, upfront. CommandBufferHelper::mUsedBuffers and ContextVk::descriptorSetCache are now FastIntegerMap CommandBufferHelper::mRenderPassUsedImages is now a FastIntegerSet Based on a CL by Jamie Bug: angleproject:4950 Test: angle_unittests.exe --gtest_filter=FastInteger* Change-Id: Ib58be20143f588baab99acadac796f2435f72d54 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2369466 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Mohan Maiya <m.maiya@samsung.com>