roll clang 150418:151385

Exciting new stuff:
* Visibility fixes, which should make it possible to get the mac components build going eventually (with a bunch of chromium patches that I have locally)
* Lambda support

This also makes -Wempty-body catch more things, so https://chromiumcodereview.appspot.com/9570054/ disables that warning on two targets.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9557011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124649 0039d316-1c4b-4281-b951-d872f2087c98

tools/clang/scripts/update.sh

@@ -8,7 +8,7 @@
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION=150418
+CLANG_REVISION=151385
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"