Refactor inheritMultifileParts to be a JVM analysis flag

Instead of a JVMConfigurationKeys key. This will allow to use it in a
checker in 'frontend.java'

compiler/frontend.java/src/org/jetbrains/kotlin/config/JVMConfigurationKeys.java

@@ -69,8 +69,6 @@ public class JVMConfigurationKeys {
             CompilerConfigurationKey.create("do not throw NPE on explicit 'equals' call for null receiver of platform boxed primitive type");
     public static final CompilerConfigurationKey<Boolean> DISABLE_OPTIMIZATION =
             CompilerConfigurationKey.create("disable optimization");
-    public static final CompilerConfigurationKey<Boolean> INHERIT_MULTIFILE_PARTS =
-            CompilerConfigurationKey.create("compile multifile classes to a hierarchy of parts and facade");
     public static final CompilerConfigurationKey<Boolean> USE_TYPE_TABLE =
             CompilerConfigurationKey.create("use type table in serializer");
 

compiler/frontend.java/src/org/jetbrains/kotlin/config/JvmAnalysisFlags.kt

@@ -14,4 +14,7 @@ object JvmAnalysisFlags {
 
     @JvmStatic
     val jvmDefaultMode by AnalysisFlag.Delegates.JvmDefaultModeDisabledByDefault
+
+    @JvmStatic
+    val inheritMultifileParts by AnalysisFlag.Delegates.Boolean
 }