RFR: 8320763: Fix spacing arround assignment in spec.gmk.in

Mon Nov 27 14:22:25 UTC 2023

For some reason, we have not been consistent with using spaces around the assignment operators (`:=` and `=`) in spec.gmk.in. This has annoyed me for a long time.

When making this change, I noticed that there are a lot of late evaluation assignments (= instead of :=) that should not be there. To not confuse the code review, I will fix these separately. Thus this change will only change whitespace.

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Commit messages:
 - Merge branch 'master' into spec-cleanup-whitespace
 - 8320763: Fix spacing arround assignment in spec.gmk.in

Changes: https://git.openjdk.org/jdk/pull/16825/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16825&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320763
  Stats: 351 lines in 1 file changed: 0 ins; 0 del; 351 mod
  Patch: https://git.openjdk.org/jdk/pull/16825.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16825/head:pull/16825

PR: https://git.openjdk.org/jdk/pull/16825