Implement operator-is for interfaces' supertypes and String's supertypes. Also, improve stack trace…

dart/tests/co19/co19-leg.status

Index: dart/tests/co19/co19-leg.status
diff --git a/dart/tests/co19/co19-leg.status b/dart/tests/co19/co19-leg.status
index 705ff3b2bcba542846f052142a3f89e2f635e76c..c78d20f7f06471429ff6ca32d95dcef6bfbac749 100644
--- a/dart/tests/co19/co19-leg.status
+++ b/dart/tests/co19/co19-leg.status
@@ -172,6 +172,7 @@ Language/06_Functions/06_Functions_A03_t01: Fail # Cannot find value
 Language/06_Functions/2_Formal_Parameters/2_Named_Optional_Formals_A01_t01: Fail # CompileTimeConstantHandler non-primitive list-entries not implemented
 Language/07_Classes/7_Static_Variables_A04_t01: Fail # SsaBuilder.visitContinueStatement not implemented
 Language/07_Classes/8_Superclasses/1_Inheritance_and_Overriding_A02_t03: Fail # SsaBuilder.visitIdentifier on non-this
+Language/13_Types/4_Interface_Types_A07_t03: Fail # SsaBuilder.visitContinueStatement not implemented
 Language/13_Types/4_Interface_Types_A09_t01: Fail # Cannot find value
 Language/13_Types/5_Function_Types_A02_t03: Fail # Cannot find value
 Language/13_Types/5_Function_Types_A02_t05: Fail # Cannot find value
@@ -319,12 +320,9 @@ LibTest/core/List/removeRange_A02_t01: Fail # Fixed length array.
 LibTest/core/List/addLast_A02_t01: Fail # Fixed length array.
 
 
-LibTest/core/Date/compareTo_A01_t01: Fail # Fail is Comparable test.
 LibTest/core/Date/timeZone_A01_t01: Fail # Should throw NoSuchMethodException.
 LibTest/core/Date/value_A01_t01: Fail # Should throw NoSuchMethodException.
-LibTest/core/Duration/compareTo_A01_t01: Fail # Fail is Comparable test.
 LibTest/core/Math/parseDouble_A02_t01: Fail # TODO(ahe): Reject bad values.
-LibTest/core/String/String_class_A03_t01: Fail # Implement is-checks.
 LibTest/core/Queue/iterator_A01_t01: Fail # Implement is-checks.
 
 
@@ -353,10 +351,7 @@ LangGuideTest/02_Language_Constructs/02_1_Class/02_1_Class_Canonicalization/02_1
 LangGuideTest/05_Equality/05_1_Object_Identity_Equality/05_1_Object_Identity_Equality_A01_t01: Fail # Expect.isTrue(false) fails.
 LangGuideTest/05_Equality/05_1_Object_Identity_Equality/05_1_Object_Identity_Equality_A01_t03: Fail # Expect.isTrue(false) fails.
 LangGuideTest/05_Equality/05_2_Value_Equality/05_2_Value_Equality_A01_t01: Fail # Expect.isTrue(false) fails.
-Language/13_Types/4_Interface_Types_A02_t01: Fail # Expect.isTrue(false) fails.
-Language/13_Types/4_Interface_Types_A04_t02: Fail # Expect.isTrue(false) fails.
 Language/13_Types/4_Interface_Types_A05_t03: Fail # Expect.isTrue(false) fails.
-Language/13_Types/4_Interface_Types_A11_t04: Fail # Expect.isTrue(false) fails.
 Language/13_Types/5_Function_Types_A02_t01: Fail # Expect.isTrue(false) fails.
 Language/13_Types/5_Function_Types_A02_t02: Fail # Expect.isTrue(false) fails.
 LibTest/core/Object/operator_equality_A01_t01: Fail # Expect.isTrue(false) fails.