Fix variadic reg saving / unused register copy output
Fix variadic reg saving / unused register copy output

Previously every store to the stack would generate a load into a
pointer register which would be unused. The store is flushed
regardless, so we don't need a volatile-flush for the returned
pointer from the stack-save call.

bobrippling/ucc-c-compiler,bobrippling/ucc-c-compiler,bobrippling/ucc-c-compiler