Add --mangle-regex option

lib/propmangle.js

@@ -64,7 +64,8 @@ function mangle_properties(ast, options) {
     options = defaults(options, {
         reserved : null,
         cache : null,
-        only_cache : false
+        only_cache : false,
+        regex : null
     });
 
     var reserved = options.reserved;
@@ -79,6 +80,8 @@ function mangle_properties(ast, options) {
         };
     }
 
+    var regex = options.regex;
+
     var names_to_mangle = [];
 
     // step 1: find candidates to mangle
@@ -149,6 +152,7 @@ function mangle_properties(ast, options) {
     }
 
     function should_mangle(name) {
+        if (regex && !regex.test(name)) return false;
         if (reserved.indexOf(name) >= 0) return false;
         return cache.props.has(name)
             || names_to_mangle.indexOf(name) >= 0;