Auto merge of #110807 - petrochenkov:strictflavor, r=lqd,wesleywiser

linker: Report linker flavors incompatible with the current target

The linker flavor is checked for target compatibility even if linker is never used (e.g. we are producing a rlib).
If it causes trouble, we can move the check to `link.rs` so it will run if the linker (flavor) is actually used.

And also feature gate explicitly specifying linker flavors for tier 3 targets.

The next step is supporting all the internal linker flavors in user-visible interfaces (command line and json).

Author: bors