RFR: 8378580: Make ArrayDeque bulk add methods bootstrap-proof

[Eirik Bjørsnøs]

Please review this small change to avoid loading lambda machinery in `ArrayDeque.addAll` and `ArrayDeque(Collection)`.

Core collections like these may be useful in early bootstrap where we want to avoid eager loading of lambda machinery.  JDK-8375580 recently showed one example where `URLClassPath` was avoiding these bulk-adding methods exactly to avoid triggering lambdas.

This PR replaces the use of `Collection.forEach` with a plain old for loop.

This was initially discussed here: https://mail.openjdk.org/pipermail/core-libs-dev/2026-February/159362.html

Cleanup, low risk enhancement, `noreg-cleanup`.

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Commit messages:
 - Use simple loop instead of lambda in ArrayDeque bulk adds

Changes: https://git.openjdk.org/jdk/pull/29894/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29894&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378580
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/29894.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29894/head:pull/29894

PR: https://git.openjdk.org/jdk/pull/29894