zimg 2.3

set minimum macOS requirement of >= 10.11 and remove the fix in the
formula since upstream says

  This won't be fixed. Upgrade your CLANG version to 3.8 (XCode 7.3?),
  so that it will be compatible with ICC/ICL.

Formula/zimg.rb

@@ -1,8 +1,8 @@
 class Zimg < Formula
   desc "Scaling, colorspace conversion, and dithering library"
   homepage "https://github.com/sekrit-twc/zimg"
-  url "https://github.com/sekrit-twc/zimg/archive/release-2.2.1.tar.gz"
-  sha256 "0ac3004f7612f91e2eda1aaaf170c2ceef4f90f881647b8e248f36b0e6954f54"
+  url "https://github.com/sekrit-twc/zimg/archive/release-2.3.tar.gz"
+  sha256 "09962385f986dbcfd8ed6160cdafc2bc57bef8c6bfb3ca3a4bcaa482f09c06fa"
   head "https://github.com/sekrit-twc/zimg.git"
 
   bottle do
@@ -17,22 +17,10 @@ class Zimg < Formula
   depends_on "automake" => :build
   depends_on "libtool" => :build
 
-  needs :cxx11 if MacOS.version < :mavericks
+  # Upstream has decided not to fix https://github.com/sekrit-twc/zimg/issues/52
+  depends_on :macos => :el_capitan
 
   def install
-    ENV.cxx11 if MacOS.version < :mavericks
-
-    # Fixes "error: use of undeclared identifier '_mm256_cvtph_ps'"
-    # See https://reviews.llvm.org/rL254528 for the underlying cause
-    # Reported 4 Sep 2016 https://github.com/sekrit-twc/zimg/issues/52
-    if MacOS.version < :el_capitan
-      (buildpath/"brew_include/immintrin.h").write <<-EOS.undent
-        #include <x86intrin.h>
-        #include_next <immintrin.h>
-      EOS
-      ENV.prepend "CPPFLAGS", "-I#{buildpath}/brew_include"
-    end
-
     system "./autogen.sh"
     system "./configure", "--prefix=#{prefix}"
     system "make", "install"