[8u20] backport RFR (XL) 8031320: Use Intel RTM instructions for locks

[Vladimir Kozlov]

These changes were pushed into jdk9 last week.
Changes from jdk9 applied to 8u without conflicts but I have to modify flags because this optimization will be only 
experimental in 8u20: all RTM flags in globals_x86.hpp are experimental for 8u20 (in jdk9 3 main flags were product).

http://cr.openjdk.java.net/~kvn/8031320_8u/webrev/

https://bugs.openjdk.java.net/browse/JDK-8031320
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/2f459c5235f9
http://cr.openjdk.java.net/~kvn/8031320_9/webrev/

I also will backport additional related small fixes:

https://bugs.openjdk.java.net/browse/JDK-8038181
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/7067df8672a0

https://bugs.openjdk.java.net/browse/JDK-8038286
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/2c76e6e9c04e

Thanks,
Vladimir