pub fn LLVMExtAddAttrsOnReturn(
    context: LLVMContextRef,
    function: LLVMValueRef,
    attrs: &[LLVMExtAttribute],
) {
    unsafe {
        add_attrs(context, function, attrs, LLVMAttributeReturnIndex);
    }
}
Add attributes on an LLVM return value.
weld/src/codegen/llvm2/llvm_exts.rs