This avoid recreating the GPU context for each individual
tests. This reduces the overhead drastically.
Excluding static_shaders and texture_pool tests I get for GPUVulkanTest:
`Before: 129 tests from 1 test suite ran. (26304 ms total) `
`After: 129 tests from 1 test suite ran. (6965 ms total) `
Including static_shaders and texture_pool tests I get for GPUMetalTest:
`Before: 124 tests from 1 test suite ran. (54654 ms total)`
`After: 124 tests from 1 test suite ran. (1870 ms total)`
Given the tests are run twice for the workarounds versions, the
speedup can be multiplied by 2.
Overall tests time is still largely dominated by shader compilation time.
However, there is still 3x improvement using this patch:
Including static_shaders and texture_pool tests I get for GPUVulkanTest,
GPUVulkanWorkaroundTest, GPUOpenGLTest, GPUOpenGLWorkaroundTest:
`Before: 516 tests from 4 test suites ran. (318878 ms total)`
`After: 516 tests from 4 test suites ran. (106593 ms total)`
Pull Request: https://projects.blender.org/blender/blender/pulls/138097
ca013ae67a