Translator incapable to generate TypeStruct EntryPoint parameters

clang following spir calling convention will generate byval pointer on a kernel if a structure is passed as kernel argument, see https://godbolt.org/z/c994q86xr .

Translator generates SPIR-V following input LLVM IR 1:1 and also generates byval pointer. Meanwhile in SPIR-V it's not disallowed to use directly TypeStruct EntryPoint parameter, and in some cases it's a missing optimization opportunity.

Need to investigate if we can promote byval pointer and if it breaks anything end-2-end

Start with the linked Godbolt example and trace how the translator handles the clang-generated LLVM IR byval pointer for a kernel structure argument. Investigate whether promoting it to a SPIR-V TypeStruct EntryPoint parameter preserves end-to-end behavior; done means the approach is validated without breaking existing translation.

Written by the indexing model from the issue text.