7044486: open jdk repos have files with incorrect copyright headers, which can end up in src bundles
Reviewed-by: ohair, trims

Summary: Do not synchronize on self while writing hash table elements
Reviewed-by: alanb, mduigou
Contributed-by: NNeil Richards <neil.richards@ngmr.net>

Summary: No longer synchronize on self while writing other objects.
Reviewed-by: alanb, forax, mduigou, peterjones
Contributed-by: NNeil Richards <neil.richards@ngmr.net>