-Zlink-native-libraries=no causes link to fail with missing __libc_start_main on fuchsia

[tmandry]

This test, which is built with -Zlink-native-libraries=no -Cdefault-linker-libraries=yes, fails on fuchsia with a linker error due to missing __libc_start_main.

The feature (#70093) it's trying to test should work on Fuchsia (and probably Windows? it isn't clear why that's disabled), so filing this issue to track that.

[ChrisDenton]

The problem with Windows was that -Cdefault-linker-libraries=yes is a no-op on MSVC. On most platforms rustc calls another compiler which knows how to find and pass default libraries to the linker. Whereas on MSVC, rustc calls the linker directly so there's no one else to find the libraries except us. I'm fixing the test on Windows by adding some manual linker arguments so the libs get passed in (see #134918).

I don't know if fuchsia has a similar issue.