Last gyp patch for cross-platform Unix support

third_party/libxml/libxml.gyp

Index: third_party/libxml/libxml.gyp
diff --git a/third_party/libxml/libxml.gyp b/third_party/libxml/libxml.gyp
index 2a1a6c8dc34e42330d23a2f3bd40b9a8f6ea8075..85aeadce0ceccdc9a3f82a3c8f2db19004b2ef1c 100644
--- a/third_party/libxml/libxml.gyp
+++ b/third_party/libxml/libxml.gyp
@@ -7,7 +7,7 @@
     'conditions': [
       # Define an "os_include" variable that points at the OS-specific generated
       # headers.  These were generated by running the configure script offline.
-      ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris"', {
+      ['os_posix == 1 and OS != "mac"', {
         'os_include': 'linux'
       }],
       ['OS=="mac"', {'os_include': 'mac'}],
@@ -19,8 +19,7 @@
     {
       'target_name': 'libxml',
       'conditions': [
-        ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris") '
-         'and use_system_libxml', {
+        ['os_posix == 1 and OS != "mac" and use_system_libxml', {
           'type': 'settings',
           'direct_dependent_settings': {
             'cflags': [
@@ -38,7 +37,7 @@
               '<!@(pkg-config --libs-only-l libxml-2.0)',
             ],
           },
-        }, { # else: OS != "linux" or ! use_system_libxml
+        }, { # else: os_posix != 1 or OS == "mac" or ! use_system_libxml
           'type': 'static_library',
           'msvs_guid': 'F9810DE8-CBC3-4605-A7B1-ECA2D5292FD7',
           'sources': [