Change all hashbangs to /usr/bin/env (#9057)

Summary:
```
git grep -l '#!' | xargs sed -i 's|#!.*/bin/\([^ ]*\)$|#!/usr/bin/env \1|'
```
and some manual tweaking

Test Plan: harbormaster

Reviewers: austin

Subscribers: hvr, simonmar, ezyang, carter

Differential Revision: https://phabricator.haskell.org/D237

GHC Trac Issues: #9057

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/count_bytes b/compiler/count_bytes
index bf6240228f..4b8aa37898 100644
--- a/compiler/count_bytes
+++ b/compiler/count_bytes
@@ -1,4 +1,4 @@
-#! /usr/local/bin/perl
+#!/usr/bin/env perl
 #
 %DirCount = ();
 %ModCount = ();