RFR: JDK-8244044 Refactor phase makefiles to be structured per module

Tue Apr 28 22:13:23 UTC 2020

This is a refactoring that is long time overdue. In fact, it should have 
been done as part of the original Jigsaw implementation, but because 
Reasons this did not happen.

This change will turn the include structure "inside out" for the phase 
specific make files (e.g. gensrc, lib, copy, ...). So instead of 
grouping all gensrc files together, now all e.g. jdk.compiler files are 
grouped together. This will present a clearer picture of the overall 
needs of the respective modules.

I expect to post additional patches to make the structure shine. For 
instance, the files moved to "common/modules" certainly warrants a 
second look on where they actually belong (perhaps as part of 
ModuleWrapper?), and if they really are needed.

This bug ties in with JDK-8241463, JDK-8055193 and JDK-8055192.

Bug: https://bugs.openjdk.java.net/browse/JDK-8244044
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8244044-refactor-module-phase-files/webrev.01

/Magnus