Implement support for pre-built SPIR-V binaries

vk-build-programs utility can be used to build and store SPIR-V
binaries.

If glslang is not available, test framework will attempt to load
pre-built binaries from vulkan/prebuilt directory.

scripts/build_vulkan_programs.py can be used to populate
data/vulkan/prebuilt directory with SPIR-V binaries.

Change-Id: I1e998bba0e0021d0e5b6da35ed53c54a61207bff
8 files changed