Merge pull request swiftlang#12571 from gooichi/hotfix-fix-swift-project-settings

Author: swift-ci

utils/swift-project-settings.el

@@ -369,7 +369,7 @@ libraries that require a single frontend invocation" )
 
 (defconst swift-project-stdlib-aux-swiftc-args
   (append swift-project-single-frontend-swiftc-args
-          (list -sil-serialize-vtables" "-parse-stdlib"))
+          (list "-sil-serialize-vtables" "-parse-stdlib"))
   "swiftc arguments for library components that are compiled as
   though they are part of the standard library even though
   they're not strictly in that binary."  )