Synthetic methods generated by Kotlin compiler for suspend functions should not cause discovery errors

[marcphilipp]

Steps to reproduce

See

• Spring Boot 4.0.0-RC1: JUnit test discovery fails depending on a Kotlin test name spring-projects/spring-framework#35693

For every suspend function m, the Kotlin compiler generates a synthetic, static method m$suspendImpl that looks like a suspend function. However, since it's synthetic, lookups for the corresponding KFunction return null.

JUnit should not consider such synthetic methods as suspend functions and avoid the lookup and the subsequent failure.

Context

• Used versions (Jupiter/Vintage/Platform): 6.0.0
• Build Tool/IDE: irrelevant

Deliverables

• Avoid reporting discovery errors for synthetic methods that look like suspend functions