[Platform API] Make 'ModuleInfo.platform' non-nullable

compiler/cli/cli-common/src/org/jetbrains/kotlin/analyzer/common/CommonResolverForModuleFactory.kt

@@ -38,6 +38,7 @@ import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.load.kotlin.MetadataFinderFactory
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.platform.CommonPlatforms
 import org.jetbrains.kotlin.platform.TargetPlatform
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.resolve.*
@@ -67,6 +68,9 @@ object CommonResolverForModuleFactory : ResolverForModuleFactory() {
         override fun dependencyOnBuiltIns(): ModuleInfo.DependencyOnBuiltIns =
             if (dependOnOldBuiltIns) ModuleInfo.DependencyOnBuiltIns.LAST else ModuleInfo.DependencyOnBuiltIns.NONE
 
+        override val platform: TargetPlatform
+            get() = CommonPlatforms.defaultCommonPlatform
+
         override val compilerServices: PlatformDependentCompilerServices
             get() = CommonPlatformCompilerServices
     }