This is a renamed copy of the r3354 wrapper script existing for WebRTC located
in trunk/tools/valgrind-webrtc/ of WebRTC (with suppressions cleaned).

Using the libyuv_tests.[sh,bat] script, it is possible to run the libyuv
unit tests under memory tools like Valgrind memcheck, Thread Sanitizer and
Address Sanitizer.

Adding this directory to libyuv makes it possible to handle suppressions
entirely in libyuv, instead of depending on manually setting up the WebRTC
wrapper script on the buildbots.
Having this directory in libyuv is identical to the current buildbot setup in
terms of execution, but will make the buildbot code cleaner.

It also makes it convenient for libyuv developers to run memory tests.

Examples:
memcheck: tools/valgrind-libyuv/libyuv_tests.sh -t
out/Debug/libyuv_unittest
tsan: tools/valgrind-libyuv/libyuv_tests.sh --tool=tsan -t
out/Debug/libyuv_unittest
asan: tools/valgrind-libyuv/libyuv_tests.sh --tool=asan -t
out/Debug/libyuv_unittest

BUG=none
TEST=Ran the command lines listed above.
Review URL: https://webrtc-codereview.appspot.com/1023009

git-svn-id: http://libyuv.googlecode.com/svn/trunk@533 16f28f9a-4ce2-e073-06de-1de4eb20be90