Don't allow escaping newlines in single line strings.

dart/tests/language/language.status

Index: dart/tests/language/language.status
diff --git a/dart/tests/language/language.status b/dart/tests/language/language.status
index c68321dd2d46a0eae9f59951919b1ac99a5c7e55..efb9d283b03f0ae0127a2e767170a6e179e1679e 100644
--- a/dart/tests/language/language.status
+++ b/dart/tests/language/language.status
@@ -61,6 +61,10 @@ NamedParameters4Test: Fail
 
 UnaryPlusNegativeTest: Fail # Issue 1229
 
+# Issue 1350.
+StringEscape1NegativeTest: Fail
+StringEscape4NegativeTest: Fail
+
 
 # DartC or Frog specific tests that should not be run by the VM
 *DartcTest: Skip
@@ -185,6 +189,11 @@ PseudoKWIllegalTest/15: Fail # Issue 356
 PseudoKWIllegalTest/16: Fail # Issue 356
 DuplicateImplementsTest: Skip # Issue 976
 
+# Issue 1351.
+StringEscape1NegativeTest: Fail
+StringEscape4NegativeTest: Fail
+
+
 # VM or Frog specific tests that should not be run by DartC.
 *VMTest: Skip
 *VMNegativeTest: Skip
@@ -322,6 +331,10 @@ NamedParameters2Test: Fail
 NamedParameters3Test: Fail
 NamedParameters4Test: Fail
 
+# Issue 1352
+StringEscape3NegativeTest: Fail
+StringEscape4NegativeTest: Fail
+
 
 [ $component == webdriver && ($browser == ff || $browser == safari) ]
 MethodInvocationTest: Fail