Optimize retaining most specific methods in LazyJavaScope

See 62a55b7b00
Previously, it was working for O(n^2)
Now, we first group it by jvm descriptor,
then for each groups of size g_i finding the most specific for O(g_i^2)

It should help for the cases when we have a lot of overloads with
different JVM descriptors (modulo return type)
NB: Having the same JVM descriptors is rather rare, because
in Java one cannot generate such a class.

Looks like it's only possible for Scala or some other JVM languages (KT-17560)

It should help a lot for KT-35135

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/descriptors/LazyJavaScope.kt

@@ -35,12 +35,11 @@ import org.jetbrains.kotlin.load.java.structure.JavaArrayType
 import org.jetbrains.kotlin.load.java.structure.JavaField
 import org.jetbrains.kotlin.load.java.structure.JavaMethod
 import org.jetbrains.kotlin.load.java.structure.JavaValueParameter
+import org.jetbrains.kotlin.load.kotlin.computeJvmDescriptor
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.DescriptorFactory
-import org.jetbrains.kotlin.resolve.DescriptorUtils
+import org.jetbrains.kotlin.resolve.*
 import org.jetbrains.kotlin.resolve.constants.StringValue
 import org.jetbrains.kotlin.resolve.descriptorUtil.firstArgument
-import org.jetbrains.kotlin.resolve.retainMostSpecificInEachOverridableGroup
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindExclude.NonExtensions
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
@@ -116,13 +115,23 @@ abstract class LazyJavaScope(
     private val functions = c.storageManager.createMemoizedFunction<Name, Collection<SimpleFunctionDescriptor>> { name ->
         val result = LinkedHashSet<SimpleFunctionDescriptor>(declaredFunctions(name))
 
-        result.retainMostSpecificInEachOverridableGroup()
+        result.retainMostSpecificMethods()
 
         computeNonDeclaredFunctions(result, name)
 
         c.components.signatureEnhancement.enhanceSignatures(c, result).toList()
     }
 
+    private fun MutableSet<SimpleFunctionDescriptor>.retainMostSpecificMethods() {
+        val groups = groupBy { it.computeJvmDescriptor(withReturnType = false) }.values
+        for (group in groups) {
+            if (group.size == 1) continue
+            val mostSpecificMethods = group.selectMostSpecificFromOverridableGroup()
+            removeAll(group)
+            addAll(mostSpecificMethods)
+        }
+    }
+
     protected open fun JavaMethodDescriptor.isVisibleAsFunction() = true
 
     protected data class MethodSignatureData(