RFR: JDK-8153685: Parfait integration missing in the new tools (jmod and jlink)

[Erik Joelsson]

Hello,

These are open changes necessary for running the build with an Oracle 
internal tool.

This patch moves the definitions of the make variables JLINK and JMOD to 
configure so that custom configure logic may override and change them.

I also moved the order of javac flags around so that if JAVAC_FLAGS is 
set on the command line, it is added last and so overrides what the 
makefiles define when possible.

Bug: https://bugs.openjdk.java.net/browse/JDK-8153685
Webrev: http://cr.openjdk.java.net/~erikj/8153685/webrev.top.01/

/Erik