[Bug target/105576] x86: Support a machine constraint to get raw symbol name

[i at maskray dot me via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105576

Fangrui Song <i at maskray dot me> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #11 from Fangrui Song <i at maskray dot me> ---
Thanks to HJ for landing the GCC patch (milestone: 15?) for me.

Note that I made a typo in the commit message. "Ws" should typically be used
with the modifier 'p'

    ```
    namespace ns { extern int var; }
    asm (".pushsection .xxx,\"aw\"; .dc.a %p0; .popsection" :: "Ws"(&var));
    asm (".reloc ., BFD_RELOC_NONE, %p0" :: "Ws"(&var));
    ```

The upcoming Clang 18 release will also support "Ws".

For software utilizing this feature, for aarch64 and riscv, use the constraint
"S".