Add a no precompiled header Linux build to builds-tier1 and jdk-submit

A recent discussion on build-dev brought out the need for jdk-submit to include a build with precompiled headers disabled. We currently have such builds in builds-tier2, which is not part of jdk-submit. In tier2 now, we actually build all slowdebug builds without pch, which is overkill on platform coverage and not as useful as fastdebug builds.

My suggestion is then to add a specialized linux build of just hotspot, fastdebug and disabled pch to builds-tier1 and remove the disabling of pch on the slowdebug builds in tier2.