Add minimum nonUniform tests to descriptor indexing texts

Add minimum nonUniform tests to descriptor indexing texts

In some cases glslangValidator generates more nonUniform
decorations in the SPIR-V than is needed by the
descriptor_indexing extension. These new tests use SPIR-V
shaders to be sure that only the minimum nonUniform
decorations are in the shaders. This tests that drivers
can handle these cases.

VK-GL-CTS Issue: 2268

Affected Tests:

dEQP-VK.descriptor_indexing.storage_buffer_minNonUniform
dEQP-VK.descriptor_indexing.storage_texel_buffer_minNonUniform
dEQP-VK.descriptor_indexing.uniform_texel_buffer_minNonUniform
dEQP-VK.descriptor_indexing.uniform_buffer_minNonUniform
dEQP-VK.descriptor_indexing.combined_image_sampler_minNonUniform
dEQP-VK.descriptor_indexing.combined_image_sampler_with_lod_minNonUniform
dEQP-VK.descriptor_indexing.storage_image_minNonUniform

Components: Vulkan

Change-Id: I99d1803cff733ef85f190162526c3f9792202b09