fix: escape property names in compat mode (#1736)

Author: nknapp

lib/handlebars/compiler/javascript-compiler.js

@@ -16,7 +16,12 @@ JavaScriptCompiler.prototype = {
     return this.internalNameLookup(parent, name);
   },
   depthedLookup: function(name) {
-    return [this.aliasable('container.lookup'), '(depths, "', name, '")'];
+    return [
+      this.aliasable('container.lookup'),
+      '(depths, ',
+      JSON.stringify(name),
+      ')'
+    ];
   },
 
   compilerInfo: function() {