RFR(S): 7143038: SIGSEGV in assert_equal / LinearScan::assign_reg_num

[Roland Westrelin]

glibc's exit is called through jvmti which triggers the call of destructors for global variables such as:
LocationValue         _illegal_value = LocationValue(Location());

An example call stack:

#8  0x01056b7f in LocationValue::~LocationValue() (this=0x1a07470)
   at /tmp/roland/hotspot/src/share/vm/ci/ciConstant.hpp:73
#9  0x01039b42 in __tcf_5 ()
   at /tmp/roland/hotspot/src/share/vm/c1/c1_LinearScan.cpp:2472
#10 0x007ca209 in exit () from /lib/i686/nosegneg/libc.so.6
#11 0x0011f6c2 in forceExit (exit_code=15)
   at ../../../src/share/back/debugInit.c:635
#12 0x0011c7e8 in doExit (in=0x8d549edc, out=0x8d549d7c)
   at ../../../src/share/back/VirtualMachineImpl.c:624
#13 0x00122643 in debugLoop_run () at ../../../src/share/back/debugLoop.c:172
#14 0x00136d8f in connectionInitiated (t=0x485e50)
   at ../../../src/share/back/transport.c:261
#15 0x00136dd0 in attachThread (jvmti_env=0x830dc1c, jni_env=0x84a2940,
   arg=0x485e50) at ../../../src/share/back/transport.c:334
#16 0x0141c1fb in JvmtiAgentThread::call_start_function (this=0x84a2800)
   at /tmp/roland/hotspot/src/share/vm/prims/jvmtiImpl.cpp:90
#17 0x0141c2ad in JvmtiAgentThread::start_function_wrapper (thread=0x84a2800,
   __the_thread__=0x84a2800)
   at /tmp/roland/hotspot/src/share/vm/prims/jvmtiImpl.cpp:84
#18 0x016811b7 in JavaThread::thread_main_inner() ()
   at /tmp/roland/hotspot/src/share/vm/runtime/thread.cpp:1546
#19 0x01683cfb in JavaThread::run (this=0x84a2800)
   at /tmp/roland/hotspot/src/share/vm/runtime/thread.cpp:1523
#20 0x0154c7fb in java_start (thread=0x84a2800)
   at /tmp/roland/hotspot/src/os/linux/vm/os_linux.cpp:887
#21 0x00933869 in start_thread () from /lib/i686/nosegneg/libpthread.so.0
#22 0x0087213e in clone () from /lib/i686/nosegneg/libc.so.6

The virtual table pointers of the C++ objects are updated to the one of ResourceObj. A compilation may still be in progress at the same time and perform a virtual call on one of the global objects, leading to a call to an erroneous address and a crash.

http://cr.openjdk.java.net/~roland/7143038/webrev/