7143858: G1: Back to back young GCs with the second GC having a minimally sized eden Summary: Before the last thread to leave a JNI critical region was able to schedule a GCLocker Initiated GC, another thread was attempting an allocation and saw that the GCLocker region was no longer active and successfully scheduled a GC. Stall allocating threads until the GCLocker Initiated GC is performed and then retry the allocation. Reviewed-by: brutisso, huntch

os_family = bsd

arch = zero

arch_model = zero

os_arch = bsd_zero

os_arch_model = bsd_zero

lib_arch = zero

compiler = gcc

gnu_dis_arch = zero

sysdefs = -D_ALLBSD_SOURCE -D_GNU_SOURCE -DCC_INTERP -DZERO -D@ZERO_ARCHDEF@ -DZERO_LIBARCH=\"@ZERO_LIBARCH@\"