Split up list of package files in build process, to work around xcode limits.

pkg/pkg_files.gyp

Index: pkg/pkg_files.gyp
diff --git a/pkg/pkg_files.gyp b/pkg/pkg_files.gyp
index 78a751ff7a87ec76e3cbe0f6be1859263e4e1ed6..afb09cf9726c36d5baaa5ec1f2e02d3f4dadabef 100644
--- a/pkg/pkg_files.gyp
+++ b/pkg/pkg_files.gyp
@@ -4,10 +4,13 @@
 
 {
   'targets': [
-    # Other targets depend on pkg files, but have to many inputs, which causes
+    # Other targets depend on pkg files, but have too many inputs, which causes
     # issues on some platforms.
     # This target lists all the files in pkg and third_party/pkg,
-    # and creates a single pkg_files.stamp
+    # and creates the timestamp pkg_files.stamp, which depends on some
+    # intermediate helper timestamps.
+    # We split third_party/pkg up into three groups, based on the last
+    # character before .dart at the end of the filename.
     {
       'target_name': 'pkg_files_stamp',
       'type': 'none',
@@ -17,7 +20,9 @@
           'inputs': [
             '../tools/create_timestamp_file.py',
             '<!@(["python", "../tools/list_files.py", "\\.dart$", "."])',
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_1.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_2.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_3.stamp',
           ],
           'outputs': [
             '<(SHARED_INTERMEDIATE_DIR)/pkg_files.stamp',
@@ -28,15 +33,47 @@
           ],
         },
         {
-          'action_name': 'make_third_party_pkg_files_stamp',
+          'action_name': 'make_third_party_pkg_files_1_stamp',
           'inputs': [
             '../tools/create_timestamp_file.py',
             '<!@(["python", "../tools/list_files.py",'
-                '"^(?!.*_test.dart).*dart$",'
+                '"^(?!.*_test\.dart).*[a-k]\.dart$",'
                 '"../third_party/pkg"])',
           ],
           'outputs': [
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_1.stamp',
+          ],
+          'action': [
+            'python', '../tools/create_timestamp_file.py',
+            '<@(_outputs)',
+          ],
+        },
+        {
+          'action_name': 'make_third_party_pkg_files_2_stamp',
+          'inputs': [
+            '../tools/create_timestamp_file.py',
+            '<!@(["python", "../tools/list_files.py",'
+                '"^(?!.*_test\.dart).*[l-r]\.dart$",'
+                '"../third_party/pkg"])',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_2.stamp',
+          ],
+          'action': [
+            'python', '../tools/create_timestamp_file.py',
+            '<@(_outputs)',
+          ],
+        },
+        {
+          'action_name': 'make_third_party_pkg_files_3_stamp',
+          'inputs': [
+            '../tools/create_timestamp_file.py',
+            '<!@(["python", "../tools/list_files.py",'
+                '"^(?!.*_test\.dart).*[^a-r]\.dart$",'
+                '"../third_party/pkg"])',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_3.stamp',
           ],
           'action': [
             'python', '../tools/create_timestamp_file.py',