The driver reports via VkPhysicalDeviceDescriptorIndexingFeatures that shaderSampledImageArrayNonUniformIndexing is available. So it should be legal to call the following code in a shader:
layout (...) uniform sampler2DMSArray textures2DMSArray[some size];
...
color = texelFetch(textures2DMSArray[nonuniformEXT(textureIndex)], ivec3(uv * size, layer), int(sample));
But it's crashing the driver. It doesn't crash when removing nonuniformEXT. The callstack goes quite deep:
amdvlk64.dll!00007fffc4ccc444() Unknown
amdvlk64.dll!00007fffc4ccc568() Unknown
amdvlk64.dll!00007fffc4ccc65f() Unknown
amdvlk64.dll!00007fffc4cb6e07() Unknown
amdvlk64.dll!00007fffc4b591c8() Unknown
amdvlk64.dll!00007fffc4b5afe6() Unknown
amdvlk64.dll!00007fffc4b74e4d() Unknown
amdvlk64.dll!00007fffc4acb689() Unknown
amdvlk64.dll!00007fffc4aeb02c() Unknown
amdvlk64.dll!00007fffc4ad026b() Unknown
amdvlk64.dll!00007fffc4875717() Unknown
amdvlk64.dll!00007fffc4a23120() Unknown
amdvlk64.dll!00007fffc48eb759() Unknown
amdvlk64.dll!00007fffc48e3e42() Unknown
amdvlk64.dll!00007fffc48e53a1() Unknown
amdvlk64.dll!00007fffc4873803() Unknown
amdvlk64.dll!00007fffc467ca20() Unknown
amdvlk64.dll!00007fffc462a135() Unknown
amdvlk64.dll!00007fffc46768ca() Unknown
amdvlk64.dll!00007fffc463636c() Unknown
The dll being loaded at 00007FFFC45F0000-00007FFFC6C99000
