Enable cross-lang-fat-lto on Linux

[NobodyXu]

Fixed #806

• Add new feature flag cross-lang-fat-lto and enable it on release for linux
• Enable -C linker-plugin-lto for linux
• Only use -Z gcc-ld=lld on non-windows targets when cargo-zigbuild is not enabled

Signed-off-by: Jiahao XU [email protected]

[NobodyXu]

before
after

It seems that enabling cross-lang-fat-lto is extremely effective at reducing binary size.
It reduces the size by at least 50% or even more.

I suppose that the linker is able to remove the code related to zstd compression support, since that is probably not used.

@passcod Seems like we should also do this for macos and windows, but they seems to be much harder than linux.
Enabling this on macos gives strange link time error like --plugin-opt not supported and on windows they use msvc by default.

[NobodyXu]

I've tested the aarch64-unknown-linux-{gnu, musl} inside docker desktop on MacOS and they somehow stuck at "Looking up crate information".

htop shows that one of the thread is running forever, so it could be deadlock or could it be a miscompilation?

I will investigate on this latter.
@passcod It would be great if you could help me on this.

[NobodyXu]

I will investigate on this latter.

I've submit PR #818 to test this.