RFR: 8318447: Move NMT source code to own subdirectory [v8]

[Johan Sjölen]

> I think that NMT is deserving of its own subdirectory. Can we do a review of the changes before I fix the merge conflicts?
> 
> 1. Moved all the nmt source code from services/ to nmt/
> 2. Renamed all the include statements and sorted them
> 3. Fixed the include guards

Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:

  Stefan's suggestions

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16276/files
  - new: https://git.openjdk.org/jdk/pull/16276/files/70b39e41..bb72984b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16276&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16276&range=06-07

  Stats: 6 lines in 4 files changed: 2 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16276.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16276/head:pull/16276

PR: https://git.openjdk.org/jdk/pull/16276