Fix strip on non-x86 targets

[taiki-e]

There are dedicated stripping tools for architectures other than x86. If they are installed, use them; otherwise, skip strip.

Fixes #8

cc @Shadow53

[Shadow53]

This looks like it would do the job! Thanks for being so quick about this.

A question, out of curiosity: why run *-strip --version instead of something like which *-strip or I think command -q strip (running the program vs just searching for it)?

[Shadow53]

I am trying this branch in my CI to test, and I am still getting the same error:

 strip: Unable to recognise the format of the input file `hoard'

This is with the following Rust toolchains:

• aarch64-unknown-linux-gnu
• aarch64-unknown-linux-musl
• arm-unknown-linux-gnueabihf
• arm-unknown-linux-musleabihf

Notably, the following successfully built:

• aarch64-linux-android
• arm-linux-androideabi
• armv7-linux-androideabi

It looks like the successful ones were not stripped, as aarch64-linux-android does not match the pattern aarch64*-unknown-linux-* and I did not have the right cross-compilation tools installed for the other two.

I will update with another comment if I figure anything else out.

[Shadow53]

The Android aarch64 target does not contain -unknown

[Shadow53]

Okay, I think I found the issue, You set strip="..." in the case statement, but around line 111 you call strip instead of $strip. Change it to the latter, and I think the issue I saw will go away.

[taiki-e]

Thanks @Shadow53! I've applied both fixes.

[taiki-e]

A question, out of curiosity: why run *-strip --version instead of something like which *-strip or I think command -q strip (running the program vs just searching for it)?

I tried to choose the one that worked most reliably because their subtle differences in behavior are complicated (koalaman/shellcheck#1162), but in fact strip --version did not work on macos, so I switched to which in latest commit.

[taiki-e]

I've tested that these work (https://github.com/taiki-e/test/actions/runs/1286975387). merging