Every time an exception object is created, the constructor calls `fillInStackTrace()`, which has to walk the call stack to record every frame. This is expensive, and it's also unnecessary if the exception is never thrown. There are a few instances in various parts of the JDK libraries where we create an exception in the dominator block but don't always throw it. This patch fixes those cases so that if the exception is not going to be thrown, it is never created in the first place.
--------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Only create exception objects if we're going to throw them Changes: https://git.openjdk.org/jdk/pull/31487/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=31487&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8386509 Stats: 41 lines in 6 files changed: 12 ins; 8 del; 21 mod Patch: https://git.openjdk.org/jdk/pull/31487.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/31487/head:pull/31487 PR: https://git.openjdk.org/jdk/pull/31487
