[clang] [llvm] [Clang][BPF] Allow sign extension for call parameters with int types (PR #84874)

[Pu Lehui via cfe-commits]

pulehui wrote:

> @pulehui I will not merge this patch now since it does not really solve the whole riscv issue. As @4ast commented above, the verifier made btf_func_model to jit.
> [snip]
> So you will know whether it is a struct or signed or not. If you feel you need explicit UNSIGNED flag, you can add it in btf as well.
> 
> Let us try to resolve the issue in riscv backend. Thanks!

Thanks Yonghong and Alexei, will try to resolve this incompatibility between bpf abi and riscv abi.

https://github.com/llvm/llvm-project/pull/84874