[analyzer] Fix bugs in generate_files script.

- task_dependency_graph no longer exists.
- summary/generate.dart expects an IDL file, it fails
  when run without any args. There's only one such
  file in the repo so I passed that.

Change-Id: I63854acc070c1cf4c49bb82d03f1312930e447e5
Tested: Ran the script, it generates all files without errors.
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/255481
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
diff --git a/pkg/analyzer/tool/generate_files b/pkg/analyzer/tool/generate_files
index 92ce05c..0528a82 100755
--- a/pkg/analyzer/tool/generate_files
+++ b/pkg/analyzer/tool/generate_files
@@ -43,5 +43,4 @@
 
 cd "${SCRIPT_DIR}"
 "${DART}" "${VM_OPTIONS[@]}" "messages/generate.dart"
-"${DART}" "${VM_OPTIONS[@]}" "summary/generate.dart"
-"${DART}" "${VM_OPTIONS[@]}" "task_dependency_graph/generate.dart"
+"${DART}" "${VM_OPTIONS[@]}" "summary/generate.dart" "${ROOT_DIR}/pkg/analyzer/lib/src/summary/idl.dart"