Repost: RFR (S) JDK-6311046: -Xcheck:jni should support checking of GetPrimitiveArrayCritical

[David Simms]

Gidday all:

Bug/Enhancement: https://bugs.openjdk.java.net/browse/JDK-6311046

Web review: http://cr.openjdk.java.net/~dsimms/6311046/rev4/

Cleaned up the "hand rolled" memory bounds checking in 
os::malloc/realloc/free and type checking in checked JNI (GetString*), 
and unified into a single helper class "GuardedMemory". Added some extra 
checks to checked JNI (release mode).

There is now some extra debugging support for free/release operations, 
GuardedMemory::release_for_freeing()" will now mark user bytes with 
"freeBlockPad", which did yield a result when testing.

Testing Completed:

Ran on all platforms:

  * JPRT
  * jteg jdk_core & jdk_svc
  * "RT nightly".


Cheers
/David Simms