Add syntax files from upstream vim repository

compiler/pbx.vim

@@ -0,0 +1,24 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim compiler file
+" Compiler:	Apple Project Builder
+" Maintainer:	Alexander von Below (public@vonBelow.Com)
+" Last Change:	2004 Mar 27
+
+if exists("current_compiler")
+   finish
+endif
+let current_compiler = "pbx"
+
+if exists(":CompilerSet") != 2		" older Vim always used :setlocal
+  command -nargs=* CompilerSet setlocal <args>
+endif
+
+" The compiler actually is gcc, so the errorformat is unchanged
+CompilerSet errorformat&
+
+" default make
+CompilerSet makeprg=pbxbuild
+
+
+endif