Display description of language version in options

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/DefaultValues.kt

@@ -30,7 +30,7 @@ open class DefaultValues(val defaultValue: String, val possibleValues: List<Stri
 
     object LanguageVersions : DefaultValues(
             "\"" + LanguageVersion.LATEST_STABLE.versionString + "\"",
-            LanguageVersion.values().map { "\"${it.versionString}\"" }
+            LanguageVersion.values().map { "\"${it.description}\"" }
     )
 
     object JvmTargetVersions : DefaultValues(

compiler/cli/src/org/jetbrains/kotlin/cli/common/CLICompiler.java

@@ -317,7 +317,7 @@ public abstract class CLICompiler<A extends CommonCompilerArguments> {
         List<String> versionStrings = ArraysKt.map(LanguageVersion.values(), new Function1<LanguageVersion, String>() {
             @Override
             public String invoke(LanguageVersion version) {
-                return version.getVersionString();
+                return version.getDescription();
             }
         });
         String message = "Unknown " + versionOf + " version: " + value + "\n" +