Lables: break and continue accept only string literals

idea/testData/psi/ControlStructures.jet

@@ -3,9 +3,9 @@ fun a(
     a : foo = throw new Foo,
     a : foo = return 10,
     a : foo = break,
-    a : foo = break la,
+    a : foo = break "la",
     a : foo = continue,
-    a : foo = continue la,
+    a : foo = continue "la",
     a : foo = if (10) foo else bar,
     a : foo = if (10) foo
 ) {
@@ -13,11 +13,11 @@ fun a(
   return
   10
   break
-  la
-  break la
+  "la"
+  break "la"
   continue
-  la
-  continue la
+  "la"
+  continue "la"
   if (foo)
     if (foo)
       bar
@@ -75,6 +75,7 @@ fun a(
   do {
 
   } while (false)
+}
 
 fun foo() {
     for (a in b)

idea/testData/psi/SimpleExpressions.jet

@@ -27,9 +27,9 @@ fun a(
     a : foo = throw new Foo,
     a : foo = return 10,
     a : foo = break,
-    a : foo = break la,
+    a : foo = break "la",
     a : foo = continue,
-    a : foo = continue la,
+    a : foo = continue "la",
     a : foo = 10,
     a : foo = 10,
     a : foo = 10,
@@ -39,9 +39,9 @@ fun a(
     return
     10
     break
-    la
-    break la
+    "la"
+    break "la"
     continue
-    la
-    continue la
+    "la"
+    continue "la"
 }