RFR: 8258407: Split up CompileJavaModules.gmk into make/modules/$M/Java.gmk

[Magnus Ihse Bursie]

Right now `CompileJavaModules.gmk` contains two different part: one part with the functionality needed to compile a java module, and one part were all special requirements for all modules are listed.

The second part should be removed from `CompileJavaModules.gmk`, and instead listed directly for each individual module in `make/modules/$M/Java.gmk`.

I used a special-written shell script to automatically extract the module-specific part from CompileJavaModules.gmk into the respective Java.gmk files, to avoid risking any hard-to-detect copy/paste errors. After this I did a `sed -i` to remove the module-specific prefix. All this makes me confident that I have correctly moved the variables (I realize this is hard to verify from the patch).

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Commit messages:
 - $($(MODULE)_COPY_EXTRA) target is not used anymore
 - Remove module prefix from java variables
 - Remove debug code mistakenly pushed
 - Move some more module-specific stuff to Java.gmk files
 - Only include the module Java.gmk file we need
 - First step: break out Java settings to separate files

Changes: https://git.openjdk.java.net/jdk/pull/1779/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1779&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258407
  Stats: 2118 lines in 47 files changed: 1556 ins; 548 del; 14 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1779.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1779/head:pull/1779

PR: https://git.openjdk.java.net/jdk/pull/1779