Build: enable -Werror in stdlib/core/compiler/plugins modules

Exclude modules where there are still warnings in an explicitly declared
variable `tasksWithWarnings`.

Also remove "-progressive" from compiler arguments in modules which are
built with non-latest language version, as the warning about that leads
to an error with -Werror.

libraries/commonConfiguration.gradle

@@ -9,6 +9,8 @@ ext.configureJavaOnlyJvm6Project = { Project project ->
     }
 }
 
+List<String> tasksWithWarnings = (List<String>) rootProject.ext.get("tasksWithWarnings")
+
 ext.configureJvm6Project = { Project project ->
     project.configure(project) {
         configurations {
@@ -34,6 +36,14 @@ ext.configureJvm6Project = { Project project ->
             executable = "$JDK_16/bin/java"
         }
     }
+
+    project.tasks.withType(org.jetbrains.kotlin.gradle.dsl.KotlinCompile.class) { task ->
+        if (!tasksWithWarnings.contains(task.path)) {
+            task.kotlinOptions {
+                allWarningsAsErrors = true
+            }
+        }
+    }
 }
 
 ext.compileJava9Sources = { Project project, String moduleName, Collection<FileCollection> moduleOutputs = [project.sourceSets.main.output] ->