Use DefaultAnalyzerFacade for common code in diagnostic tests

Because of incomplete infrastructure, introduce a few dirty hacks to make
diagnostic tests analyze the common code via DefaultAnalyzerFacade, and also
add common module sources to analysis of platform-specific modules.

Also do not render 'platform' declarations from platform-specific modules to
the .txt file, since they are very likely to be exact copies of the same
declaration in the common module (see RecursiveDescriptorComparator)

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt

@@ -46,6 +46,9 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
         fqName: FqName -> LazyPackageViewDescriptorImpl(this, fqName, storageManager)
     }
 
+    @Deprecated("This method is not going to be supported. Please do not use it")
+    val testOnly_AllDependentModules: List<ModuleDescriptorImpl> get() = this.dependencies!!.allDependencies
+
     override val allDependentModules: List<ModuleDescriptor>
         get() = this.dependencies.sure { "Dependencies of module $id were not set" }.allDependencies.filter { it != this }