x264: update to r2197 and fix clang optimization

Upgrade x264 to the latest stable tarball, 20120425.
Add `ENV.O1` when compiling with clang, which fixes a segfault
when encoding with libx264.  The fps encoding rate remains the
same using this commit.  The changelog listed in the formula
comments was checked, and the version is unchanged.  This will
cause a hash fail when x264-r2184.tar.bz2 already exists.  The
user will have to remove the cached tarball and try again.  At
the time this commit is being submitted, the x264-devel mailing
listserv is offline.  So it hasn't been reported a second time.

Fixes Homebrew/homebrew#11248.
Closes Homebrew/homebrew#11885.

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

Formula/x264.rb

@@ -4,9 +4,9 @@ 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-20120327-2245-stable.tar.bz2'
-  version 'r2184'
-  md5 '0660e5829dc7f621bb98124440e38924'
+  url 'http://download.videolan.org/pub/videolan/x264/snapshots/x264-snapshot-20120425-2245-stable.tar.bz2'
+  sha1 '969e015e5df24091b5e62873808e6529a7f2fb7f'
+  version 'r2197'
 
   head 'git://git.videolan.org/x264.git'
 
@@ -17,6 +17,9 @@ 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')