neon: disable -no-cpp-precomp in configure

Formula/neon.rb

@@ -14,6 +14,12 @@ class Neon < Formula
   depends_on 'pkg-config' => :build
   depends_on 'openssl' if build.with? 'brewed-openssl'
 
+  # Configure switch unconditionally adds the -no-cpp-precomp switch
+  # to CPPFLAGS, which is an obsolete Apple-only switch that breaks
+  # builds under non-Apple compilers and which may or may not do anything
+  # anymore.
+  def patches; DATA; end
+
   def install
     ENV.universal_binary if build.universal?
     ENV.enable_warnings
@@ -32,3 +38,17 @@ class Neon < Formula
     system "make install"
   end
 end
+
+__END__
+diff --git a/configure b/configure
+index b0a7908..a0f2ceb 100755
+--- a/configure
++++ b/configure
+@@ -4224,7 +4224,6 @@ fi
+ $as_echo "$ne_cv_os_uname" >&6; }
+ 
+ if test "$ne_cv_os_uname" = "Darwin"; then
+-  CPPFLAGS="$CPPFLAGS -no-cpp-precomp"
+   LDFLAGS="$LDFLAGS -flat_namespace"
+   # poll has various issues in various Darwin releases
+   if test x${ac_cv_func_poll+set} != xset; then