Revert "libxml2: Fix Python bindings for Xcode-only"

This reverts commit 202119e0e3ee20c72940be5ff38bc36d3e331d41.

Formula/libxml2.rb

@@ -19,15 +19,6 @@ class Libxml2 < Formula
     ]
   end
 
-  def patches
-    # Libxml2 is a dupe and now we see why that's a bad idea.
-    # Python's distutils are so smart to remember the LD command from
-    # when python was built and therefore finds the libxml2 in Xcode first.
-    # The LDFLAGS don't help, because python puts them _after_ the remembered
-    # flags.
-    DATA unless MacOS::CLT.installed?
-  end
-
   def install
     ENV.universal_binary if ARGV.build_universal?
 
@@ -50,11 +41,6 @@ class Libxml2 < Formula
         ENV.append 'CFLAGS', arch_flags
         ENV.append 'LDFLAGS', arch_flags
 
-        unless MacOS::CLT.installed?
-          # For Xcode-only systems, the libiconv headers are inside of Xcode.
-          # We can replace /opt/include with our path to achieve that
-          inreplace 'setup.py', '"/opt/include",', "\"#{MacOS.sdk_path}/usr/include\","
-        end
         system "python", "setup.py", "install_lib",
           "--install-dir=#{python_lib}"
       end
@@ -65,19 +51,3 @@ class Libxml2 < Formula
     "python" + `python -c 'import sys;print(sys.version[:3])'`.strip
   end
 end
-
-__END__
-diff --git a/python/setup.py.in b/python/setup.py.in
-index b985979..d6ccf2e 100755
---- a/python/setup.py.in
-+++ b/python/setup.py.in
-@@ -13,6 +13,9 @@ ROOT = r'@prefix@'
- # Thread-enabled libxml2
- with_threads = @WITH_THREADS@
-
-+import distutils.sysconfig as sc
-+sc.get_config_vars()['LDSHARED']=os.environ['LD'] + ' -bundle -undefined dynamic_lookup -L' + ROOT + '/lib ' + os.environ['LDFLAGS']
-+
- # If this flag is set (windows only),
- # a private copy of the dlls are included in the package.
- # If this flag is not set, the libxml2 and libxslt