RFR (S) 8130039: Move the platform-specific [OS]Semaphore code

[coleen.phillimore at oracle.com]

Also:
8130038: Unify the semaphore usage in os_xxx.cpp

Tested with hs-tier1-5.  And 
open/test/jdk/sun/misc/SunMiscSignalTest.java and closed signal tests.

open webrev at http://cr.openjdk.java.net/~coleenp/8130039.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8130039

Thanks,
Coleen