linker: Move native library search from linker to rustc

[petrochenkov]

For static libraries only, for now.

Linker's search by name is still used if rustc's search fails, because linker may search in additional platform-specific directories in addition to directories known to rustc.
So we are basically doing something like #123436 for all targets.

This way we provide best effort support for +verbatim modifier even on targets with linkers not supporting it natively.
This closes #132264 in particular.

If this is supported for dynamic libraries as well (which is nontrivial), this may also allow us to not pass -L options to the linker at all, although it may cause some breakage from libraries passed to linker directly, without rustc knowing about it.

TODO: Some more tests for +verbatim and library naming fallback on Windows, if they are missing.

[rustbot]

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[rustbot]

This PR modifies run-make tests.

cc @jieyouxu

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

[wesleywiser]

I'm not sure this is correct. To my knowledge, MSVC does not use .a at all for static libs (unless we/the Rust ecosystem have started doing this somewhere). What probably does use .a though would be *-windows-gnu.

This code originated a long time ago, far before MSVC was supported: cb823b0. My hunch is that this probably needs to either be changed to target Windows generally or *-windows-gnu more specifically.

[petrochenkov]

All built-in targets except windows-msvc already have the libname.a naming scheme in their target specs, so this fallback doesn't apply to them (due to the target != unix condition). So on windows-gnu in particular the fallback is also not necessary.

unless we/the Rust ecosystem have started doing this somewhere

Meson is using the libname.a naming scheme on MSVC and CMake now also supports it due to Meson (#123436, https://mesonbuild.com/FAQ.html#why-does-building-my-project-with-msvc-output-static-libraries-called-libfooa, https://gitlab.kitware.com/cmake/cmake/-/issues/23975).

[wesleywiser]

Ok, can you mention that Meson and CMake do this in the comment?

[xclaesse]

FYI: There is a relevant issue about Windows static lib naming here: #114013 (could be outdated, I don't know if things changed in rustc since).

[bors]

☔ The latest upstream changes (presumably #138956) made this pull request unmergeable. Please resolve the merge conflicts.

[petrochenkov]

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[rustbot]

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