Feature request: flag for debugging symbols

[flip111]

Right not stack supports --no-strip and --ghc-options="-g" with which it's possible to get debugging symbols in the executable. However ...

1. cabal has it's own flag --enable-debug-info which i've been told sets -g and also -enable-dwarf-unwind. So to recreate this behaviour we get to the wieldy: stack build --no-strip --ghc-options="-g -enable-dward-unwind". To just have something like stack build --with-symbols would be much nicer.
2. Using --ghc-options bypasses cabal code, now Setup.hs scripts don't get notified that debug symbols were requested. I'm calling cmake from my Setup.hs script and i would like to compile dependencies (C code) also with symbols depending on the configuration for my library.

On a side note ...

This issue talks about passing configure options to Setup.hs and underlying Cabal code.

However it's closed with the implementation of #4750

But that PR talks about configure options for Pantry. I don't quite get how that is related, but it makes me believe that the added feature can not be used for Cabal because it's for Pantry.