minor: rename TargetBackend enum values

compiler/testData/codegen/box/bridges/objectClone.kt

@@ -1,4 +1,4 @@
-// TARGET_BACKEND: ONLY_JVM
+// TARGET_BACKEND: JVM
 import java.util.HashSet
 
 trait A : Set<String>

generators/src/org/jetbrains/jet/generators/tests/GenerateTests.kt

@@ -648,7 +648,7 @@ fun main(args: Array<String>) {
 
     testGroup("js/js.tests/test", "compiler/testData") {
         testClass(javaClass<AbstractBridgeTest>()) {
-            model("codegen/box/bridges", targetBackend = TargetBackend.ONLY_JS)
+            model("codegen/box/bridges", targetBackend = TargetBackend.JS)
         }
     }
 }

generators/src/org/jetbrains/jet/generators/tests/generator/TestGenerator.java

@@ -37,8 +37,8 @@ public class TestGenerator {
 
     public static enum TargetBackend {
         ANY,
-        ONLY_JVM,
-        ONLY_JS
+        JVM,
+        JS
     }
 
     public static final String NAVIGATION_METADATA = "navigationMetadata";