[Bug target/101275] [RISCV] Document the machine constraint 'S' and make it non-internal

[kito at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101275

Kito Cheng <kito at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kito at gcc dot gnu.org

--- Comment #1 from Kito Cheng <kito at gcc dot gnu.org> ---
I am happy to add it to document, here it the patch:

https://gcc.gnu.org/pipermail/gcc-patches/2021-July/574318.html