Auto merge of #13755 - fhartwig:early-return, r=KiChjang

Invert conditional and return early from report_pending_exception

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Previously, almost the entire body of `report_pending_exception` was in a conditional branch. We now return early if the function body does not need to be executed.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #13746 (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because they don't add any new functionality.

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