x264: use stable, fix version, rm -O1

* Specify the stable branch for the head url.
* Use http rather than git for the head url.
* Correct the version number, is 2189 for stable (2197 was master)
* Note in comments how to use version.sh to get the version number.
* Remove the -O1 for clang.  Issue is fixed in this version.

The previous commit added -O1 to fix a segfault when x264 was
compiled with clang.  The author was testing this against the
previous tarball, not 2189.  The devs emailed back explaining
that this was fixed since then, and this is confirmed to work
using their -O3 or Homebrew's -Os.  Users should remove x264
and ffmpeg and `brew install x264 ffmpeg` to get a working pair.
Apologies for all this, but it's better to get it right.

Closes Homebrew/homebrew#11908.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/x264.rb

@@ -2,13 +2,11 @@ require 'formula'
 
 class X264 < Formula
   homepage 'http://www.videolan.org/developers/x264.html'
-  # The version is _not_ 2245. See http://www.x264.nl/x264/changelog.txt for
-  # the revision numbers that are attached to each commit.
   url 'http://download.videolan.org/pub/videolan/x264/snapshots/x264-snapshot-20120425-2245-stable.tar.bz2'
   sha1 '969e015e5df24091b5e62873808e6529a7f2fb7f'
-  version 'r2197'
+  version 'r2189' # use version.sh to find this with brew install -i --HEAD x264
 
-  head 'git://git.videolan.org/x264.git'
+  head 'http://git.videolan.org/git/x264.git', :branch => 'stable'
 
   depends_on 'yasm' => :build
 
@@ -17,9 +15,6 @@ class X264 < Formula
   end
 
   def install
-    # See https://github.com/mxcl/homebrew/issues/11248
-    ENV.O1 if ENV.compiler == :clang
-
     args = ["--prefix=#{prefix}", "--enable-shared"]
     args << "--bit-depth=10" if ARGV.include?('--10-bit')