RFR: 8356390: Rename ResolvedIndyEntry::set_flags to set_has_appendix [v3]

[Johan Sjölen]

> The `set_flags` function really only sets whether it has an appendix or not, and there's a separate `set_resolution_failed` method just below that also alters the flag. Just rename this to `set_has_appendix`

Johan Sjölen has updated the pull request incrementally with two additional commits since the last revision:

 - We missed the case of has_appendix = false
 - And make the code uniform for both flags

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25092/files
  - new: https://git.openjdk.org/jdk/pull/25092/files/beccef03..4da8d47b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25092&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25092&range=01-02

  Stats: 7 lines in 1 file changed: 3 ins; 1 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/25092.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25092/head:pull/25092

PR: https://git.openjdk.org/jdk/pull/25092