Memory stomping error with PipedThreadsStressTest in 5.7 in mixed mode

This assertion happened only in 5.7 in mixed mode.

Look here for logs : /net/tetrasparc/export/mojave/dhana/Thread/5.7/mixed/ss1/..


## nof_mallocs = 3134, nof_frees = 1423
## memory stomp: byte at 0x2e6990 after object 0x2e2990
### previous object (not sure if correct): 0x2da968 (32760 bytes)
### next object: 0x2ee9d8 (-1414812757 bytes)
#
# HotSpot Virtual Machine Error, Internal Error
#
# Fatal: memory stomping error
# Error ID: /home/dhana/ws_1.0.1/build/solaris/../../src/share/vm/runtime/os.cpp
, 380 [ Patched ]
#
Dumping core....

TEST FAIL misc/threads/PipedThreadsStressTest compile_and_execute