Update runtime files.

runtime/compiler/javac.vim

@@ -1,7 +1,7 @@
 " Vim compiler file
-" Compiler:	javac
+" Compiler:	Java Development Kit Compiler
 " Maintainer:	Doug Kearns <dougkearns@gmail.com>
-" Last Change:	2004 Nov 27
+" Last Change:	2019 Oct 21
 
 if exists("current_compiler")
   finish
@@ -12,6 +12,15 @@ if exists(":CompilerSet") != 2		" older Vim always used :setlocal
   command -nargs=* CompilerSet setlocal <args>
 endif
 
-CompilerSet makeprg=javac
+let s:cpo_save = &cpo
+set cpo&vim
 
-CompilerSet errorformat=%E%f:%l:\ %m,%-Z%p^,%-C%.%#,%-G%.%#
+CompilerSet makeprg=javac
+CompilerSet errorformat=%E%f:%l:\ error:\ %m,
+		       \%W%f:%l:\ warning:\ %m,
+		       \%-Z%p^,
+		       \%-C%.%#,
+		       \%-G%.%#
+
+let &cpo = s:cpo_save
+unlet s:cpo_save