RFR: 8368102: Don't store macros in spec.gmk [v3]

[Magnus Ihse Bursie]

> We currently have three macros (as in "functions", not just simple strings) that are assigned in spec.gmk. This is in contrast with the rest of the values assigned in spec.gmk, and it is surprising and is forcing an odd syntax. Furthermore, these macros are named as constants, and not as we normally name functions/macros.
> 
> We should move them to normal .gmk code, and rename them.
> 
> The three macros are `SET_SHARED_LIBRARY_ORIGIN`, `SET_EXECUTABLE_ORIGIN` and `SET_SHARED_LIBRARY_NAME`.

Magnus Ihse Bursie has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'master' into no-macros-in-spec
 - Fix indentation
   
   Co-authored-by: Erik Joelsson <37597443+erikj79 at users.noreply.github.com>
 - 8368102: Don't store macros in spec.gmk

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27394/files
  - new: https://git.openjdk.org/jdk/pull/27394/files/812a6e53..33d252e6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27394&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27394&range=01-02

  Stats: 108640 lines in 579 files changed: 104612 ins; 1687 del; 2341 mod
  Patch: https://git.openjdk.org/jdk/pull/27394.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27394/head:pull/27394

PR: https://git.openjdk.org/jdk/pull/27394