RFR (S) 8022335 - (round 2) Native stack walk on Windows x64

[Ioi Lam]

Please review this fix:

http://cr.openjdk.java.net/~iklam/8022335/win64_stack_walk_002/

Bug: Native stack walk while generating hs_err does not work on Windows x64

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8022335
     https://bugs.openjdk.java.net/browse/JDK-8022335

What's new:

     The code is much more simplified than my last version. All interesting
     code is in a single function -- os::platform_print_native_stack
     in os_windows_x86.cpp. The rest is just busy work.

Summary of fix:

     Windows x64 binaries are built (unconditionally) with the 
equivalent of
     -fomit-frame-pointer, so HotSpot's build-in native stack walking code
     will fail to find the sender frame. As a result, hs_err on Windows/x64
     will always list a single frame.

     I have added the os::platform_print_native_stack() function for
     Windows/x64 only. It uses the StackWalk64 API to walk the stace.

     Because the Win/x64 frame layout is very different than what 
HotSpot expects,
     I decided to implement os::platform_print_native_stack() as a 
completely
     stand-alone function, and do not interact with the existing "frame" 
C++ class.
     See comments in os_windows_x86.cpp for details.

Deficiency of fix:

     StackWalk64 knows nothing about the Java frames. So hs_err will 
display only
     the native frames, and stop as soon as the first Java frame is 
reached. It will
     also NOT display any native frames below Java frames.

     Printing the Java frames *may* be possible. However, at this point, 
I want
     to keep the code simple and crash proof. I will file a different 
bug for
     printing the Java frames.

Bonus:

     As a side-fix, I refactored a bunch of duplicated code in 
decoder.cpp into
     the DecoderLocker class.

Tests:

     JPRT
     UTE (vm.runtime.testlist, vm.quick.testlist, 
vm.parallel_class_loading.testlist)

     I also manually inserted some crashes into jvm.dll and verified 
that the
     native stack trace is printed as expected on Win/x64.


Thanks
- Ioi