RFR (M) #3 CR 8003985: Support @Contended annotation

[Aleksey Shipilev]

Hi,

This is the updated webrev for JEP-142 aka @Contended:
  http://shipilev.net/pub/jdk/hotspot/contended/webrev-6/

It employs the same trick for reducing footprint: piggybacking on
InstanceKlass::misc_flags to store class-level flag, and making the
tagged field in FieldInfo (as the side effect, cleaning up the mess with
"temporarily store type into offset field") to store per-field info. I
had to fix a few compile-time errors for MSVC.

Testing:
  - Test8003985 @Contended-targeted test passed
  - JPRT full cycle passed
  - adhoc nsk, regression suites passed

I would really appreciate the reviews!

Thanks,
Aleksey.