build: link libatomic on mac and linux

Fixes nodejs#28231

PR-URL: nodejs#28232
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: devsnek

node.gyp

@@ -289,6 +289,9 @@
           '-Wl,-bnoerrmsg',
         ],
       }],
+      ['(OS=="linux" or OS=="mac") and llvm_version!=0', {
+        'libraries': ['-latomic'],
+      }],
     ],
   },