Descriptors are cached via weak references in moduleByClassLoader.kt and
can be garbage-collected at any point. So relying on identity of
descriptors in KTypeParameterImpl is dangerous because the same type
parameter can be represented by different descriptors. For example, the
test equalsOnFunctionParameters.kt was flaky before this change because
of this issue, and that could be reproduced by running it a few hundred
times in the same process.
Instead, use the type parameter's container (which is either KClass or
KCallable) and name, in equals/hashCode. KClass and KCallable already
have equals/hashCode independent of descriptors, so this works in case
the descriptor is invalidated.
Alexander Udalov
55f384cb04