[Bug target/112478] riscv: asm clobbers not honored

[andrew at sifive dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112478

--- Comment #2 from Andrew Waterman <andrew at sifive dot com> ---
Although I sketched the first draft of this patch, it’s Jeff Law who brought it
to fruition. He is more suited to help than I am.