Bug 23231: Remove our STL Wrappers workaround for Windows 64bit

The fix for https://bugzilla.mozilla.org/show_bug.cgi?id=1443823 makes
our workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=1392604
obsolete, and we can remove it as it landed on esr60.

projects/firefox/STL_win64.patch

-From 8f8c1a1069d4907d3cedae578975225d8caeecaf Mon Sep 17 00:00:00 2001
-From: Nicolas Vigier <boklm@torproject.org>
-Date: Sat, 12 Aug 2017 22:00:13 +0200
-Subject: [PATCH] Bug 23231: disable STL Wrappers on Windows
-
-Workaround for:
-https://bugzilla.mozilla.org/show_bug.cgi?id=1392604
----
- old-configure.in | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/old-configure.in b/old-configure.in
-index f5a2f05..e247551 100644
---- a/old-configure.in
-+++ b/old-configure.in
-@@ -1338,7 +1338,7 @@ MOZ_CXX11
- AC_LANG_C
- 
- case "${OS_TARGET}" in
--Darwin)
-+WINNT|Darwin)
-   ;;
- *)
-   STL_FLAGS="-I${DIST}/stl_wrappers"

projects/firefox/build

@@ -132,10 +132,6 @@ fi
   export CC='gcc -m32'
 [% END -%]
 
-[% IF c("var/windows-x86_64") %]
-  patch -p1 < $rootdir/STL_win64.patch
-[% END -%]
-
 [% IF c("var/windows") %]
   patch -p1 < $rootdir/nsis-uninstall.patch
 [% END -%]

projects/firefox/config

@@ -104,8 +104,6 @@ input_files:
   - project: gcc
     name: gcc
     enable: '[% c("var/windows") %]'
-  - filename: STL_win64.patch
-    enable: '[% c("var/windows-x86_64") %]'
   - filename: nsis-uninstall.patch
     enable: '[% c("var/windows") %]'
   - project: rust