[code-reflection] Integrated: Hat cleanup extracted examples

[Gary Frost]

Cleaning up examples and adding profiling to OpenCL ffi backend.  So we can track buffer transfer costs
Actual implementation of code to minimize buffer transfers is next...

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Commit messages:
 - whitespace and license fixes
 - let env.bash try to find jextract
 - Enqueue markers on compute start and end and on enter leave of kernel dispatch
 - Enqueue markers on compute start and end
 - Fix Bldr.java (mac osx version) and cleaned headers
 - We seem to be successfully marking buffer arg access types RO,RW and WO.
 - We seem to be successfully marking buffer arg access types RO,RW and WO.
 - Accept Short, Long and Double args
 - Nbody OpenCL mode uses HAT buffer (We need solution for OpenCL4)

Changes: https://git.openjdk.org/babylon/pull/341/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=341&range=00
  Stats: 1616 lines in 27 files changed: 908 ins; 640 del; 68 mod
  Patch: https://git.openjdk.org/babylon/pull/341.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/341/head:pull/341

PR: https://git.openjdk.org/babylon/pull/341