bugfix - Prevent redeclaring methods inside Aliases

The getMethods function gets called both in the removeDuplicateMethodsFromPhpDoc
function and in helper.php, which causes the method detection to be performed twice.

Parts of the method detection includes a check for duplicate methods, but Macro
methods for example, aren't checked for duplicates.

Instead of checking everywhere if we're not adding duplicates, I've included a
check in the getMethods call to just use the already generated methods
if they have been generated already.

src/Alias.php

@@ -176,6 +176,10 @@ class Alias
      */
     public function getMethods()
     {
+        if (count($this->methods) > 0) {
+            return $this->methods;
+        }
+
         $this->addMagicMethods();
         $this->detectMethods();
         return $this->methods;
@@ -411,10 +415,9 @@ class Alias
      */
     protected function removeDuplicateMethodsFromPhpDoc()
     {
-        $methods = count($this->methods) > 0 ? $this->methods : $this->getMethods();
         $methodNames = array_map(function (Method $method) {
             return $method->getName();
-        }, $methods);
+        }, $this->getMethods());
 
         foreach ($this->phpdoc->getTags() as $tag) {
             if ($tag instanceof MethodTag && in_array($tag->getMethodName(), $methodNames)) {