Use failedAt in more places (constants, universe)

pkg/compiler/lib/src/constants/evaluation.dart

Index: pkg/compiler/lib/src/constants/evaluation.dart
diff --git a/pkg/compiler/lib/src/constants/evaluation.dart b/pkg/compiler/lib/src/constants/evaluation.dart
index a799d17254aca5d2e5a8fede04e928872b2ee029..d94e5528b6e010e8c7ae446aa523fcba94dc139f 100644
--- a/pkg/compiler/lib/src/constants/evaluation.dart
+++ b/pkg/compiler/lib/src/constants/evaluation.dart
@@ -48,14 +48,18 @@ class NormalizedArguments {
     int index = callStructure.namedArguments.indexOf(name);
     if (index == -1) {
       // The named argument is not provided.
-      invariant(CURRENT_ELEMENT_SPANNABLE, defaultValues[name] != null,
-          message: "No default value for named argument '$name' in $this.");
+      assert(
+          defaultValues[name] != null,
+          failedAt(CURRENT_ELEMENT_SPANNABLE,
+              "No default value for named argument '$name' in $this."));
       return defaultValues[name];
     }
     ConstantExpression value =
         arguments[index + callStructure.positionalArgumentCount];
-    invariant(CURRENT_ELEMENT_SPANNABLE, value != null,
-        message: "No value for named argument '$name' in $this.");
+    assert(
+        value != null,
+        failedAt(CURRENT_ELEMENT_SPANNABLE,
+            "No value for named argument '$name' in $this."));
     return value;
   }
 
@@ -63,13 +67,17 @@ class NormalizedArguments {
   ConstantExpression getPositionalArgument(int index) {
     if (index >= callStructure.positionalArgumentCount) {
       // The positional argument is not provided.
-      invariant(CURRENT_ELEMENT_SPANNABLE, defaultValues[index] != null,
-          message: "No default value for positional argument $index in $this.");
+      assert(
+          defaultValues[index] != null,
+          failedAt(CURRENT_ELEMENT_SPANNABLE,
+              "No default value for positional argument $index in $this."));
       return defaultValues[index];
     }
     ConstantExpression value = arguments[index];
-    invariant(CURRENT_ELEMENT_SPANNABLE, value != null,
-        message: "No value for positional argument $index in $this.");
+    assert(
+        value != null,
+        failedAt(CURRENT_ELEMENT_SPANNABLE,
+            "No value for positional argument $index in $this."));
     return value;
   }