Handle two different revisions in create_release.py (one for asserts) (#977)

diff --git a/scripts/create_release.py b/scripts/create_release.py
index 2d239c2..2003031 100755
--- a/scripts/create_release.py
+++ b/scripts/create_release.py
@@ -28,18 +28,21 @@
   release_info = emsdk.load_releases_info()
   new_version = version_key(release_info['aliases']['latest'])[0]
   new_version[-1] += 1
-  branch_name = 'version_%s' % '_'.join(str(part) for part in new_version)
-
-  # Create a new git branch
-  subprocess.check_call(['git', 'checkout', '-b', branch_name], cwd=root_dir)
 
   new_version = '.'.join(str(part) for part in new_version)
+  asserts_hash = None
   if args:
     new_hash = args[0]
+    if len(args) > 1:
+      asserts_hash = args[1]
   else:
     new_hash = emsdk.get_emscripten_releases_tot()
   print('Creating new release: %s -> %s' % (new_version, new_hash))
   release_info['releases'][new_version] = new_hash
+  if asserts_hash:
+    asserts_name = new_version + '-asserts'
+    release_info['releases'][asserts_name] = asserts_hash
+
   releases = [(k, v) for k, v in release_info['releases'].items()]
   releases.sort(key=lambda pair: version_key(pair[0]))
 
@@ -50,7 +53,12 @@
     f.write(json.dumps(release_info, indent=2))
     f.write('\n')
 
-  subprocess.check_call(os.path.join(script_dir, 'update_bazel_workspace.sh'), cwd=root_dir)
+  subprocess.check_call([os.path.join(script_dir, 'update_bazel_workspace.sh')], cwd=root_dir)
+
+  branch_name = 'version_%s' % '_'.join(str(part) for part in new_version)
+
+  # Create a new git branch
+  subprocess.check_call(['git', 'checkout', '-b', branch_name], cwd=root_dir)
 
   # Create auto-generated changes to the new git branch
   subprocess.check_call(['git', 'add', '-u', '.'], cwd=root_dir)