Add syntax files from upstream vim repository

syntax/bzl.vim

@@ -0,0 +1,20 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim syntax file
+" Language:	Bazel (http://bazel.io)
+" Maintainer:	David Barnett (https://github.com/google/vim-ft-bzl)
+" Last Change:	2015 Aug 11
+
+if exists('b:current_syntax')
+  finish
+endif
+
+
+runtime! syntax/python.vim
+
+let b:current_syntax = 'bzl'
+
+syn region bzlRule start='^\w\+($' end='^)\n*' transparent fold
+syn region bzlList start='\[' end='\]' transparent fold
+
+endif