Summary: Make two G1 cmd line flags available in product builds: G1HeapWastePercent (previously called: G1OldReclaimableThresholdPercent) and G1MixedGCCountTarget (previous called: G1MaxMixedGCNum). Also changed the default of the former from 1% to 5% and the default for G1OldCSetRegionLiveThresholdPercent to 90%.
Reviewed-by: azeemj, jwilhelm, johnc

Summary: Attempting to initiate a marking cycle when allocating a humongous object can, if a marking cycle is successfully initiated by another thread, result in the allocating thread spinning until the marking cycle is complete. Eliminate a deadlock between the main ConcurrentMarkThread, the SurrogateLocker thread, the VM thread, and a mutator thread waiting on the SecondaryFreeList_lock (while free regions are going to become available) by not manipulating the pending list lock during the prologue and epilogue of the cleanup pause.
Reviewed-by: brutisso, jcoomes, tonyp

Reviewed-by: jcoomes, brutisso

Summary: Detect cygwin prescence when setting up PLATFORM. Translate cygwin style paths before passing them on to jtreg.
Reviewed-by: jcoomes, brutisso

Reviewed-by: brutisso

Reviewed-by: jcoomes