<AWT Dev> Request for review: 8026385: [macosx] (awt) setjmp/longjmp changes the process signal mask on OS X

[David DeHaven]

JBS Issue:
https://bugs.openjdk.java.net/browse/JDK-8026385

Webrev:
http://cr.openjdk.java.net/~ddehaven/8026385/jdk.0/

Basically extends the work Staffan performed for https://bugs.openjdk.java.net/browse/JDK-8023786

Verified by running:
find build/macosx-x86_64-normal-server-fastdebug/jdk/objs -name '*.o' -exec nm -u {} \; | egrep '(setjmp|longjmp)'

With this change, all references in jdk were __setjmp or __longjmp (two underscores), there are no remaining references to _setjmp/_longjmp in jdk with this change.

-DrD-