We can than compile the TS version of the lib, for the targeted Lua version using TSTL.

This wasn't done before, because the library used some low level Lua functionality which at the time was hard or impossible to replicate with TSTL. With language-extensions it should be straight forward to port it.

Since we use the library in a bunch of places (testing, website, benchmarks). It might make sense to move it to an extra package.

Originally posted by @lolleko in #1263 (comment)

Out of scope for this PR, but we should thing about, rewriting this lib in TS and compiling it for the different versions before injecting into the test runner.