RFR: JDK-8019540: licensee reports a JDK8 build failure after 8005849/8005008 fixes integrated.

[Erik Joelsson]

Please review the following changes, correcting the conditions for when 
to build certain parts of the servicability features. Instead of 
guarding them with the OPENJDK variable, they need to be conditioned on 
the existence of the source itself.

In hotspot, this only fails on Windows. The linux makefiles already 
check on the existence of the source rather than if it's an OPENJDK 
build. This change makes windows do the same.

http://cr.openjdk.java.net/~erikj/8019540/webrev.hotspot.01/

In JDK, it fails on all platforms. There is already a configure 
variable, ENABLE_JFR, that seems to be set correctly for this case.

http://cr.openjdk.java.net/~erikj/8019540/webrev.jdk.01/

I will need a sponsor to push this to hotspot if it passes review.

/Erik