RFR: 8321159: SymbolLookup.libraryLookup(Path, Arena) Assumes default Filesystem

[Per Minborg]

This PR proposes to reject paths provided to the `SymbolLookup.libraryLookup(Path path, Arena arena)` method if a path is not in the default file system.

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Commit messages:
 - Fix logic
 - Reject paths not in the default file system

Changes: https://git.openjdk.org/jdk/pull/16944/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16944&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321159
  Stats: 5 lines in 1 file changed: 5 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16944.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16944/head:pull/16944

PR: https://git.openjdk.org/jdk/pull/16944