This patch series optimizes programs that use the pattern:

for (;;) {
  glVertexAttribPointer(...)
  glDraw(...)
}

Change 5: Re-check fragment opts on necessary changes.

Check on a program binding change and on a sample coverage enabled
chagne. This likely could be optimized further for program binding
changes.

In total the patch series reduces test iteration time by 25%.

Test: DrawCallPerfBenchmark.Run/vulkan_attrib_change
Bug: angleproject:5045
Bug: b/168493024
Change-Id: I5116f228d5eeef6606136a9a0cc81a4545df9d33
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2409177
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>