RFR: 8297964: Jetty.java fails "assert(_no_handle_mark_nesting == 0) failed: allocating handle inside NoHandleMark"

Greetings, this small change resolves the assertions on no_handle_mark_nesting, a problem resulting from continuations requiring handles for stack walking. Issue only in debug builds. Testing: jdk_jfr Thanks Markus ------------- Commit messages: - 8297964 Changes: https://git.openjdk.org/jdk/pull/11534/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11534&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8297964 Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/11534.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11534/head:pull/11534 PR: https://git.openjdk.org/jdk/pull/11534