Add ./tools/test.py -c precompiler -r dart_precompiled.

tools/testing/dart/test_options.dart

Index: tools/testing/dart/test_options.dart
diff --git a/tools/testing/dart/test_options.dart b/tools/testing/dart/test_options.dart
index a376f28270f05996f75cfb902a6396c58ff471a6..92514fe97e7055b7afb7b0549d0b047e0ae5d4ab 100644
--- a/tools/testing/dart/test_options.dart
+++ b/tools/testing/dart/test_options.dart
@@ -67,7 +67,7 @@ class TestOptionsParser {
    dart2analyzer: Perform static analysis on Dart code by running the analyzer
           (only valid with the following runtimes: none)''',
               ['-c', '--compiler'],
-              ['none', 'dart2js', 'dart2analyzer'],
+              ['none', 'precompiler', 'dart2js', 'dart2analyzer'],
               'none'),
           // TODO(antonm): fix the option drt.
           new _TestOptionSpecification(
@@ -75,6 +75,9 @@ class TestOptionsParser {
               '''Where the tests should be run.
     vm: Run Dart code on the standalone dart vm.
 
+    dart_precompiled: Run a precompiled snapshot on a variant of the standalone
+                      dart vm lacking a JIT.
+
     d8: Run JavaScript from the command line using v8.
 
     jsshell: Run JavaScript from the command line using firefox js-shell.
@@ -95,7 +98,8 @@ class TestOptionsParser {
     none: No runtime, compile only (for example, used for dart2analyzer static
           analysis tests).''',
               ['-r', '--runtime'],
-              ['vm', 'd8', 'jsshell', 'drt', 'dartium', 'ff', 'firefox',
+              ['vm', 'dart_precompiled', 'd8', 'jsshell', 'drt', 'dartium',
+               'ff', 'firefox',
                'chrome', 'safari', 'ie9', 'ie10', 'ie11', 'opera',
                'chromeOnAndroid', 'safarimobilesim',
                'ContentShellOnAndroid', 'DartiumOnAndroid', 'none'],
@@ -644,6 +648,9 @@ Note: currently only implemented for dart2js.''',
       case 'dart2analyzer':
         validRuntimes = const ['none'];
         break;
+      case 'precompiler':
+        validRuntimes = const ['dart_precompiled'];
+        break;
       case 'none':
         validRuntimes = const ['vm', 'drt', 'dartium',
                                'ContentShellOnAndroid', 'DartiumOnAndroid'];