[Bug target/94173] [RISCV] Superfluous stackpointer manipulation

[wilson at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94173

--- Comment #3 from Jim Wilson <wilson at gcc dot gnu.org> ---
I was looking at the rv32 output.  For the rv64 compiler, you need to use
aligned(16).