Enhanced vim support.

This brings the utils/vim folder into a more vim-like format by moving
the syntax hightlighting files into a syntax subdirectory. It adds
some minimal settings that everyone should agree on to ftdetect/ftplugin and
features a new indentation plugin for .ll files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235369 91177308-0d34-0410-b5e6-96231b3b80d8

utils/vim/ftplugin/llvm.vim

@@ -0,0 +1,11 @@
+" Vim filetype plugin file
+" Language: LLVM Assembly
+" Maintainer: The LLVM team, http://llvm.org/
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal softtabstop=2 shiftwidth=2
+setlocal expandtab

utils/vim/ftplugin/tablegen.vim

@@ -0,0 +1,12 @@
+" Vim filetype plugin file
+" Language: LLVM TableGen
+" Maintainer: The LLVM team, http://llvm.org/
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+setlocal matchpairs+=<:>
+setlocal softtabstop=2 shiftwidth=2
+setlocal expandtab