Autobuilder is now running the build performance tests, its not yet adding the results data for release builds though (or being run as part of a release build)
a-full now contains perf build tests: http://git.yoctoproject.org/cgit.cgi/yocto-autobuilder2/commit/?id=5cdf5df8b17e96d9f935c2b73b113ea5b3fbd555