Refactor: drop redundant abstractions in IdeaModuleInfoTest
Split ModuleSourceInfo into ModuleProductionSourceInfo and ModuleTestSourceInfo
Introduce ModuleDescriptor#isFriend(ModuleDescriptor)

Use it to allow friend modules to see internal members
Make test source module a friend of production source module
Use different scope in completion/autoimport if element is in production source root
Debugger tests: do not print line numbers in stdlib
Minor, tests: rename test directive in debugger tests
Minor, fix warnings in KotlinClassFileIndex
Fix obscure typo in isEqual() in KotlinClassFileIndex
JS backend: improve PatternBuilder
JS backend: convert NumberConversionFIF to Kotlin
JS backend: refactoring support for binary intrinsic operations