Adds facilities for extracting Intl.message calls and generating code from translations

pkg/intl/test/message_extraction/find_output_directory.dart

Index: pkg/intl/test/message_extraction/find_output_directory.dart
diff --git a/pkg/intl/test/message_extraction/find_output_directory.dart b/pkg/intl/test/message_extraction/find_output_directory.dart
new file mode 100644
index 0000000000000000000000000000000000000000..bb623893c00d9a0b1b85ef2b49322f51541afd57
--- /dev/null
+++ b/pkg/intl/test/message_extraction/find_output_directory.dart
@@ -0,0 +1,19 @@
+/**
+ * A shared library for finding the valu eof the --output-dir parameter
+ * which all of these programs use.
+ */
+library find_output_directory;
+
+const directiveName = '--output-dir=';
+
+_asString(list) => new String.fromCharCodes(list);
+
+findOutputDirectory(List<String> args) {
+  var directive = args.firstWhere(
+      (x) => x.contains(directiveName),
+      orElse: () => null);
+  if (directive == null) return '.';
+  var file = directive.codeUnits.skip(directiveName.length);
+  return _asString(file);
+}
+