Add illumos compilation support

[Toasterson]

Testing this locally for https://github.com/Solarm-Project/solarm-gate

[coveralls]

Pull Request Test Coverage Report for Build 3863964546

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
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• Overall coverage remained the same at 84.557%

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Totals
Change from base Build 3505825334:	0.0%
Covered Lines:	334
Relevant Lines:	395

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💛 - Coveralls

[otavio]

@Toasterson any idea why this broke MacOS?

[Toasterson]

I had that error on a couple systems aswell. pkg-config can't find iconv.

Seems to have been going on for a while when I look into the CI.

mabe brew install iconv helps

 --- stderr
  thread 'main' panicked at 'Unable to find libarchive: `PKG_CONFIG_ALLOW_SYSTEM_CFLAGS="1" PKG_CONFIG_ALLOW_SYSTEM_LIBS="1" PKG_CONFIG_PATH="/usr/local/Cellar/libarchive/3.6.2/lib/pkgconfig" "pkg-config" "--libs" "--cflags" "libarchive" "libarchive >= 3.2.0"` did not exit successfully: exit status: 1
  error: could not find system library 'libarchive' required by the 'compress-tools' crate

  --- stderr
  Package iconv was not found in the pkg-config search path.
  Perhaps you should add the directory containing `iconv.pc'
  to the PKG_CONFIG_PATH environment variable
  Package 'iconv', required by 'libarchive', not found
  ', src/build.rs:14:10
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...