Rollup merge of rust-lang#112109 - Alexendoo:unsupported-split-debugi…

…nfo, r=b-naber

Don't print unsupported split-debuginfo modes with `-Zunstable-options`

Currently unsupported `split-debuginfo` options are enabled by `-Zunstable-options`, for projects that have `-Zunstable-options` for other reasons this can be [an unexpected interaction](rust-lang/rust-clippy#10516 (comment))

This PR makes it so that `--print split-debuginfo -Zunstable-options` doesn't print unsupported modes, so that a cargo config of e.g.

```toml
[profile.dev]
split-debuginfo = "unpacked"
```

Would not cause an unsupported mode to be enabled on `x86_64-pc-windows-msvc`

compiler/rustc_driver_impl/src/lib.rs

@@ -771,9 +771,7 @@ fn print_crate_info(
                 use rustc_target::spec::SplitDebuginfo::{Off, Packed, Unpacked};
 
                 for split in &[Off, Packed, Unpacked] {
-                    let stable = sess.target.options.supported_split_debuginfo.contains(split);
-                    let unstable_ok = sess.unstable_options();
-                    if stable || unstable_ok {
+                    if sess.target.options.supported_split_debuginfo.contains(split) {
                         safe_println!("{split}");
                     }
                 }