RFR: 8368102: Don't store macros in spec.gmk [v2]

[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 incrementally with one additional commit since the last revision:

  Fix indentation
  
  Co-authored-by: Erik Joelsson <37597443+erikj79 at users.noreply.github.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27394/files
  - new: https://git.openjdk.org/jdk/pull/27394/files/5a259541..812a6e53

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27394&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27394&range=00-01

  Stats: 5 lines in 1 file changed: 0 ins; 0 del; 5 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