Report messages instead of just printing.

pkg/front_end/lib/src/fasta/fasta.dart

Index: pkg/front_end/lib/src/fasta/fasta.dart
diff --git a/pkg/front_end/lib/src/fasta/fasta.dart b/pkg/front_end/lib/src/fasta/fasta.dart
index d9a483ee768435debdd887dd8fefd68115055346..5b916c11e972879e4686e0a32883be584dfc73b3 100644
--- a/pkg/front_end/lib/src/fasta/fasta.dart
+++ b/pkg/front_end/lib/src/fasta/fasta.dart
@@ -29,6 +29,8 @@ import 'dill/dill_target.dart' show DillTarget;
 
 import 'compile_platform.dart' show compilePlatformInternal;
 
+import 'severity.dart' show Severity;
+
 import 'ticker.dart' show Ticker;
 
 import 'uri_translator.dart' show UriTranslator;
@@ -79,7 +81,8 @@ Future<KernelTarget> outline(List<String> arguments) async {
     });
   } on deprecated_InputError catch (e) {
     exitCode = 1;
-    print(e.deprecated_format());
+    CompilerContext.current
+        .report(deprecated_InputError.toMessage(e), Severity.error);
     return null;
   }
 }
@@ -97,7 +100,8 @@ Future<Uri> compile(List<String> arguments) async {
     });
   } on deprecated_InputError catch (e) {
     exitCode = 1;
-    print(e.deprecated_format());
+    CompilerContext.current
+        .report(deprecated_InputError.toMessage(e), Severity.error);
     return null;
   }
 }