WIP: haskell: Make linkWithGold use gold also for compiling Setup.hs

[nh2]

Motivation for this change

linkWithGold only uses ld.gold for the final link, not for building Setup.hs (which currently takes up to ~3 seconds on my machine for each Haskell package, which can add up to some time.)

This doesn't work yet

This is WIP because it segfaults.

If I try it on the hello Haskell package, I get a segfault when running ./Setup:

niklas@ares:/tmp/nix-build-hello-1.0.0.2.drv-1/hello-1.0.0.2$ ./Setup 
Segmentation fault (core dumped)

gdb shows:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x00007ffff7ad0c81 in frame_dummy ()
   from /nix/store/254rgj92dhkyg7sydb7al65gflnyjd7b-gmp-6.1.2/lib/libgmp.so.10
#2  0x0000000000000000 in ?? ()

and when I compile with integer-simple:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x000000000040ac7d in frame_dummy ()
#2  0x0000000000000000 in ?? ()

Not sure what's going on, why does the Setup segfault if linked with ld.gold?

CC @basvandijk @peti

[mmahut]

Are there any updates on this pull request, please?

[cdepillabout]

I believe everything is built with gold now, so this should be okay to close.

@nh2 please feel free to re-open if this PR is still relevant.

[nh2]

We should probably link the related PRs, should be #80466 and the things linked in there.

[cdepillabout]

Ah, yeah, sorry I should have linked that.