AddJvmNameAnnotationFix: fix case with top-level functions

#KT-17209 Fixed

idea/testData/quickfix/addJvmNameAnnotation/topLevel.kt

@@ -0,0 +1,18 @@
+// "Add '@JvmName' annotation" "true"
+// WITH_RUNTIME
+
+fun <caret>bar(foo: List<String>): String {
+    return "1"
+}
+
+fun bar(foo: List<Int>): String {
+    return "2"
+}
+
+fun bar1(foo: List<Int>): String {
+    return "3"
+}
+
+fun bar2(foo: List<Int>): String {
+    return "4"
+}

idea/testData/quickfix/addJvmNameAnnotation/topLevel.kt.after

@@ -0,0 +1,19 @@
+// "Add '@JvmName' annotation" "true"
+// WITH_RUNTIME
+
+@JvmName("bar3")
+fun <caret>bar(foo: List<String>): String {
+    return "1"
+}
+
+fun bar(foo: List<Int>): String {
+    return "2"
+}
+
+fun bar1(foo: List<Int>): String {
+    return "3"
+}
+
+fun bar2(foo: List<Int>): String {
+    return "4"
+}