Add options to override locations of programs called from stack

[sjakobi]

(This issue is split off from #593.)

It should be possible to specify the locations of the programs that stack calls, like ldd or strip.

The location of gcc can be specified via --with-gcc since #2264.

[mgsloan]

Good idea! Should also share code with #652

[nh2]

This would allow stack users to link with the lld linker, see https://www.reddit.com/r/haskell/comments/63y43y/liked_linking_3x_faster_with_gold_link_10x_faster/

[kgadek]

I published #3118 as a quick solution to overriding ld and strip.

Also, my cabal (1.24.0.2) reports:

The flags --with-PROG and --PROG-option(s) can be used with the following programs:
  alex ar c2hs cpphs gcc ghc ghc-pkg ghcjs ghcjs-pkg greencard haddock happy
  haskell-suite haskell-suite-pkg hmake hpc hsc2hs hscolour jhc ld lhc lhc-pkg
  pkg-config strip tar uhc

Quite a few. The complete solution should cover them all.

I've started playing around more comprehensive code.

[davetapley]

Hi, sorry if this is unrelated:
Could this (and #593) be and underlying reason for the issue mentioned in this comment?

[mgsloan]

I've commented on that issue, I don't think it's related

[snoyberg]

Would #1438 (adding a configure-options) fully subsume this? At least for the examples given, I don't believe Stack calls these executables directly.

[snoyberg]

I believe the new configure-options feature on master will address this, closing. If someone has a use case which isn't addressed, please add some clarification.