Previously we assumed that a symbol is accessible if its containing
package is exported by module-info.java. Which was obviously wrong and
could lead to a situation where a symbol would be incorrectly accessible
if a usage module has a dependency on the symbol's module in IDEA
project terms, but does not require it in its module-info.java
#KT-18598 In Progress
In this commit, only IDE tests are added, because we look for module
declarations in the IDE across the whole project, whereas in the
compiler we should do this on the module path only and that requires
separate work (KT-18599) which is done in the following commits.
(The change in Cache.kt is needed so that
JvmModuleAccessibilityChecker.ClassifierUsage, which is an inner class,
would be injected properly.)
#KT-18598 In Progress
#KT-18599 In Progress
