Feature request: optional separate compilation unit in secondary tab(s)

[pauldreik]

Thanks for this wonderful tool!

I wanted to benchmark std::floor(), but the compiler removes the code making the benchmark pointless.

Would it be possible to have two tabs, one as the current and an additional one which is compiled and linked into the binary?

Casual users could just proceed as today and put the code in the main tab. Those who need the separate compilation unit can write the header in the main tab and the implementation in the secondary tab.