Add cl_khr_cooperative_matrix tests

[svenvh]

Add tests for the cl_khr_cooperative_matrix extension.

The extension defines various operations on cooperative matrix types. The list of tested operations is in cooperative_matrix.def. Each entry in that .def file results in a subtest.

Each subtest will iterate over all supported variants reported by the runtime and test each variant. An individual variant can be run using the --variant command line option.

This CTS suite generates textual SPIR-V and uses spirv-tools to assemble the textual SPIR-V into a SPIR-V binary.

[joselopeqti]

matAty should be the type always used for OpCooperativeMatrixLoadKHR in the copy tests.
When a unary variant is created, variant.inputA, variant.inputB and variant.inputC matrices use the same size (rows x cols).
For example, for a supported variant that uses MatrixA (64 x 16) and MatrixB (16 x 64), if the order of the copy operation is B, variant.inputA and variant.inputB will be 16x64. This results on the next SPIR-V being generated:

%sizeM = OpConstant %i32 16
%sizeK = OpConstant %i32 64
%sizeN = OpConstant %i32 64

And then matBty will be used resulting in storing a 64x64 matrix in a buffer of size 16x64

[svenvh]

Nice catch, thanks! Always using matAty would mean the OpCooperativeMatrixLoadKHR operations are only tested with Use = MatrixAKHR, whereas we should cover all Use values. I'll prepare a different fix.

[svenvh]

I've pushed a fix now; let me know if this works for you.