Fix warning about kotlin-reflect-api bundling Kotlin Runtime

This fixes the "Some JAR files in the classpath have the Kotlin Runtime
library bundled into them" warning when compiling all modules that
depend on kotlin-reflect-api. This warning is reported on jars in the
classpath which look like standard library artifacts, but in fact are
not because their manifest does not say so. With this change, we're now
writing the manifest of standard library artifacts to the resulting jar
of kotlin-reflect-api, with the standard library component name
"internal" (in fact, it doesn't affect anything here, any name would be
OK) to make the compiler believe that this is actually a standard
library jar

libraries/reflect/api/build.gradle

@@ -30,3 +30,7 @@ compileKotlin {
                             "-Xdump-declarations-to=${buildDir}/reflect-declarations.json"]
     }
 }
+
+jar {
+    manifestAttributes(manifest, project, "internal")
+}