Merge

8133951: Zero interpreter asserts in stubRoutines.cpp Summary: Allow zero sized code buffer when checking if there's enough remaining size Reviewed-by: kvn

8067339: PLAB reallocation might result in failure to allocate object in that recently allocated PLAB Summary: Properly size the PLAB to make sure that the object to allocate always has enough space in it. Reviewed-by: mgerdin, brutisso

8073146: G1 merges thread local age tables too early with global age table Summary: Move merging of age and survivor table to the end of GC. Reviewed-by: mgerdin, david

8040162: Avoid reallocating PLABs between GC phases in G1 Summary: Allocate G1ParScanThreadState at the start of GC and only deallocate at the end of GC. This automatically keeps the current PLAB intact without flushing it (and loosing lots of memory) for every reallocation. Reviewed-by: david, mgerdin

8133530: Add JFR event for evacuation statistics Summary: Introduce two new JFR events for young/old generation allocation statistics based on previous changes. Reviewed-by: ehelin, mgerdin

8073013: Add detailed information about PLAB memory usage Summary: Track and provide information about direct allocation, region end waste and failure waste for G1. Reviewed-by: jmasa, david, ehelin, mgerdin

8133470: Uses of Atomic methods in plab.hpp should be moved to .inline.hpp file Summary: Fix include file dependencies according to general guidelines for plab.hpp Reviewed-by: ehelin, mgerdin