Ensure that ClassElement.lookupConstructor fails when looking up default constructor using Selector…

tests/co19/co19-dart2js.status

Index: tests/co19/co19-dart2js.status
diff --git a/tests/co19/co19-dart2js.status b/tests/co19/co19-dart2js.status
index 1608f12a496958b409448c1ad047f8cb73e7c200..dec20841d9fde4ce5ff6310feedb77741ec5de77 100644
--- a/tests/co19/co19-dart2js.status
+++ b/tests/co19/co19-dart2js.status
@@ -514,8 +514,6 @@ LibTest/core/int/operator_addition_A01_t01: Fail, OK # co19 issue 280
 LibTest/core/double/operator_remainder_A01_t04: Fail
 
 [ $compiler == dart2js ]
-Language/07_Classes/6_Constructors/1_Generative_Constructors_A16_t07: Fail # Redirecting constructors can not use initializing formals. This bug was previously masked - compilation failed, but for different, wrong reason.
-
 Language/06_Functions/2_Formal_Parameters/2_Optional_Formals_A01_t10: Fail # TODO(ahe): Enforce optional parameter semantics.
 Language/06_Functions/2_Formal_Parameters/2_Optional_Formals_A01_t11: Fail # TODO(ahe): Enforce optional parameter semantics.
 Language/06_Functions/2_Formal_Parameters/2_Optional_Formals_A03_t03: Fail # TODO(ahe): Enforce optional parameter semantics.
@@ -829,6 +827,7 @@ Language/07_Classes/6_Constructors/3_Constant_Constructors_A03_t01: Fail # Check
 Language/07_Classes/6_Constructors/3_Constant_Constructors_A03_t02: Fail # Checks that compile-time error is produced when a class with constant constructor inherits a non-final instance variable.
 Language/07_Classes/6_Constructors_A01_t01: Fail # Checks that a compile-error is produced when a constructor's id coincides with the name of a field in the same class.
 Language/07_Classes/6_Constructors_A02_t01: Fail # Checks that a compile-error is produced when a named constructor definition does not begin with the name of its class.
+Language/07_Classes/6_Constructors/1_Generative_Constructors_A16_t07: Fail # http://dartbug.com/6242
 Language/10_Expressions/01_Constants_A16_t01: Fail # Checks that an IntegerDivisionByZeroException raised during evaluation  of a compile-time constant causes a compile-time error.
 Language/10_Expressions/01_Constants_A16_t02: Fail # Checks that an OutOfMemoryException raised during evaluation of a compile-time constant causes a compile-time error.
 Language/10_Expressions/05_Strings_A02_t46: Fail # Checks that multi-line strings that contain characters and sequences prohibited by this grammar, cause compile-time errors.