The SPIR-V 'EarlyFragmentTests' execution mode requires performing
additional per-fragment tests prior to fragment shader execution,
even if depth values computed by the shader would otherwise affect
them: https://www.khronos.org/registry/vulkan/specs/1.1/html/vkspec.html#shaders-fragment-earlytest

Bug: b/140302392
Change-Id: If5d836a35ee9cfc758243b34fad1222d1b0f1085
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/51888
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>