bug#22304: Build for Julia is not reproducible

[Ricardo Wurmus]

When building “julia” twice we get different binaries for

  $out/lib/julia/sys.so

and

  $out/lib/julia/sys-debug.so

I could not determine the exact differences, because instead of a diff I
just see something like this:

--- /gnu/store/6njfyp46b22b0wb0r0ccg2wdzjx7066g-julia-0.4.2/lib/julia/sys.so
+++ 6njfyp46b22b0wb0r0ccg2wdzjx7066g-julia-0.4.2/lib/julia/sys.so
├── objdump --disassemble --full-contents {}
│ @@ -99994,8 +99994,8 @@
│   186a00 05a3d38a 01488985 38ffffff 488b0515  .....H..8...H...
│   186a10 5b8b0148 898540ff ffff4c89 ad48ffff  address@hidden
│   186a20 ff31ffba 03000000 4c8db538 ffffff4c  .1......L..8...L
│   186a30 89f64989 f4e8b653 f0ff4889 8538ffff  ..I....S..H..8..
│   186a40 ff31ffba 03000000 488d9d28 ffffff49  .1......H..(...I
│   186a50 89de4c89 f6e89653 f0ff4889 8528ffff  ..L....S..H..(..
│   186a60 ff488b05 38d08a01 48898530 ffffff48  .H..8...H..0...H
│ -[ Too much input for diff ]                     
│ +[ Too much input for diff ]                         

...

--- 
/gnu/store/6njfyp46b22b0wb0r0ccg2wdzjx7066g-julia-0.4.2/lib/julia/sys-debug.so
+++ 6njfyp46b22b0wb0r0ccg2wdzjx7066g-julia-0.4.2/lib/julia/sys-debug.so
├── objdump --disassemble --full-contents {}
│ @@ -99994,8 +99994,8 @@
│   1869f0 01488b38 be370200 00e84257 f0ffe89d  .H.8.7....BW....
│   186a00 56f0ff66 6666662e 0f1f8400 00000000  V..ffff.........
│   186a10 554889e5 488b3e48 8b7608e8 e0fdffff  UH..H.>H.v......
│   186a20 4889c7e8 2856f0ff 5dc3660f 1f440000  H...(V..].f..D..
│   186a30 554889e5 4883ec10 64488b04 25280000  UH..H...dH..%(..
│   186a40 00488945 f848833d fb4d8d01 00740948  .H.E.H.=.M...t.H
│   186a50 8b0df24d 8d01eb1f 488d3591 ac190048  ...M....H.5....H
│ -[ Too much input for diff ]                     
│ +[ Too much input for diff ]                         
╵

~~ Ricardo