Introduce ImportingScope::computeImportedNames

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/Scopes.kt

@@ -121,12 +121,15 @@ interface ImportingScope : HierarchicalScope {
         return getContributedDescriptors(kindFilter, nameFilter, changeNamesForAliased = false)
     }
 
+    fun computeImportedNames(): Set<Name>?
+
     object Empty : BaseImportingScope(null) {
         override fun printStructure(p: Printer) {
             p.println("ImportingScope.Empty")
         }
 
         override fun definitelyDoesNotContainName(name: Name) = true
+        override fun computeImportedNames() = emptySet<Name>()
     }
 }
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/SubpackagesImportingScope.kt

@@ -48,4 +48,5 @@ class SubpackagesImportingScope(
     //TODO: kept old behavior, but it seems very strange (super call seems more applicable)
     override fun getContributedDescriptors(kindFilter: DescriptorKindFilter, nameFilter: (Name) -> Boolean, changeNamesForAliased: Boolean): Collection<DeclarationDescriptor>
             = emptyList()
+    override fun computeImportedNames() = emptySet<Name>()
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/scopes/utils/ScopeUtils.kt

@@ -122,6 +122,8 @@ private class MemberScopeToImportingScopeAdapter(override val parent: ImportingS
 
     override fun toString() = "${this::class.java.simpleName} for $memberScope"
 
+    override fun computeImportedNames() = memberScope.computeAllNames()
+
     override fun printStructure(p: Printer) {
         p.println(this::class.java.simpleName)
         p.pushIndent()