[code-reflection] Integrated: Cleanup bld.java and Script.java Reconstructed - from failed merge

[Gary Frost]

Finally got out of my merge mess (I think). 

Here we have a pruned version of hat/hat/Script.java and a cleaned up hat/hat/bld.java

After moving jextract out to cmake, and making cmake callable from maven.  I decided to cleanup hat/hat/bld.java which had a complicated 'capability' mechanism for emulating what cmake can do.    I removed all of that.  Now hat/bld.java just delegates to the same cmake files as maven.

-------------

Commit messages:
 - Cleanup bld.java and Script.java Reconstructed - from failed merge

Changes: https://git.openjdk.org/babylon/pull/405/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=405&range=00
  Stats: 3436 lines in 7 files changed: 118 ins; 3209 del; 109 mod
  Patch: https://git.openjdk.org/babylon/pull/405.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/405/head:pull/405

PR: https://git.openjdk.org/babylon/pull/405