pub fn LLVMExtAddAttrsOnParameter(
    context: LLVMContextRef,
    function: LLVMValueRef,
    attrs: &[LLVMExtAttribute],
    index: u32,
) {
    // Parameters are indexed 1..N
    unsafe {
        add_attrs(context, function, attrs, index + 1);
    }
}
Add attributes on an LLVM function parameter.

`param` indicates the parameter index.
weld/src/codegen/llvm2/llvm_exts.rs