Update .gitignore.

Review URL: http://webrtc-codereview.appspot.com/266001

git-svn-id: http://webrtc.googlecode.com/svn/trunk@886 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/.gitignore b/.gitignore
index c1d9505..540df49 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,8 +42,11 @@
 /third_party/libjpeg
 /third_party/libjpeg_turbo
 /third_party/libvpx
+/third_party/llvm-build
 /third_party/protobuf
 /third_party/yasm
+/tools/clang
 /tools/gyp
+/tools/win
 /x86-generic_out/
 /xcodebuild