Vim Support for Multidefs

Add vim highlighting support for multidefs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141238 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/vim/tablegen.vim b/utils/vim/tablegen.vim
index 3043489..0d6d3d4 100644
--- a/utils/vim/tablegen.vim
+++ b/utils/vim/tablegen.vim
@@ -14,7 +14,7 @@
 
 syn case match
 
-syn keyword tgKeyword   def let in code dag field include defm
+syn keyword tgKeyword   def let in code dag field include defm multidef
 syn keyword tgType      class int string list bit bits multiclass
 
 syn match   tgNumber    /\<\d\+\>/