[llvm] [SPIR-V] [NFC] Verify cl_intel_subgroup_local_block_io extension in SPIR-V BE (PR #118796)

[Viktoria Maximova via llvm-commits]

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+; Modified from: https://github.com/KhronosGroup/SPIRV-LLVM-Translator/test/extensions/INTEL/SPV_INTEL_subgroups/cl_intel_sub_groups.ll
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vmaksimo wrote:

This test does not have shuffle instructions. 
But the actual main difference is that input pointer to the builtins is in Local (`addrspace (3)`) instead of Global (`addrspace (1)`). `cl_intel_subgroup_local_block_io` just allows to use local ptr instread of global ptr, so no different functionality is expected to be tested except address space 


https://github.com/llvm/llvm-project/pull/118796