Original patch by Talin.
Original patch by Talin.

* Added the first LLVM unittest -- DenseMap.
* Updated mkpatch utility to include llvm/unittests dir
* Added top-level target "unittests" to run all unittests


git-svn-id: a4a6f32337ebd29ad4763b423022f00f68d1c7b7@61541 91177308-0d34-0410-b5e6-96231b3b80d8

lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx