RFR: 8219247: Enable inlining of newly introduced PlatformMonitor methods

[Claes Redestad]

Hi,

JDK-8210832 introduced a PlatformMonitor abstraction to delegate various
monitor operations directly to OS primitives. These methods are added to
os_posix.cpp, meaning they can't be inlined. Moving hot and trivial
delegating methods to .inline.hpp means a small improvement over the
current implementation.

Webrev: http://cr.openjdk.java.net/~redestad/8219247/open.00/
Bug:    https://bugs.openjdk.java.net/browse/JDK-8219247

Testing: tier1+2, verified improvements on a range of startup
benchmarks.

Note: the patch includes an untested but likely sufficient fix to AIX
code to include os_posix.inline.hpp from os_aix.inline.hpp - any help
verifying this builds and passes tests on AIX would be much appreciated.

Thanks!

/Claes