minor #2255 Simplify power (SpacePossum)

This PR was merged into the 1.x branch.

Discussion
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Simplify power

Commits
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9307bba Simplify power

lib/Twig/Node/Expression/Binary/Power.php

@@ -12,6 +12,10 @@ class Twig_Node_Expression_Binary_Power extends Twig_Node_Expression_Binary
 {
     public function compile(Twig_Compiler $compiler)
     {
+        if (PHP_VERSION_ID >= 50600) {
+            return parent::compile($compiler);
+        }
+
         $compiler
             ->raw('pow(')
             ->subcompile($this->getNode('left'))

test/Twig/Tests/Fixtures/expressions/power.test

@@ -0,0 +1,20 @@
+--TEST--
+Twig parses power expressions
+--TEMPLATE--
+{{ 2**3 }}
+{{ (-2)**3 }}
+{{ (-2)**(-3) }}
+{{ a ** a }}
+{{ a ** b }}
+{{ b ** a }}
+{{ b ** b }}
+--DATA--
+return array('a' => 4, 'b' => -2);
+--EXPECT--
+8
+-8
+-0.125
+256
+0.0625
+16
+0.25