Add debug strings to frontend scopes-related structures

Such as:
- PackageFragmentProviders, and, in particular,
CompositePackageFragmentProviders
- JavaPackageFragments
- Scopes produced by those providers

The rationale is that a lot of frontend-facing bugs (like red code) are
easily recognizeable in resolution. But at that point you just see a
bunch of scopes, without meaningful toStrings, you don't know who has
produced them, and what's exactly wrong.

With this commit it should make debugging slightly easier: now at least
you'll be able to see that "this scope is a scope of package fragment
for foo.bar of module baz" and decide whether the declaration should or
should not have been resolved from such scope.

core/descriptors.runtime/src/org/jetbrains/kotlin/descriptors/runtime/components/RuntimeModuleData.kt

@@ -92,7 +92,12 @@ class RuntimeModuleData private constructor(
             )
 
             module.setDependencies(module)
-            module.initialize(CompositePackageFragmentProvider(listOf(javaDescriptorResolver.packageFragmentProvider, builtinsProvider)))
+            module.initialize(
+                CompositePackageFragmentProvider(
+                    listOf(javaDescriptorResolver.packageFragmentProvider, builtinsProvider),
+                    "CompositeProvider@RuntimeModuleData for $module"
+                )
+            )
 
             return RuntimeModuleData(
                 deserializationComponentsForJava.components,