Merge pull request #648 from RyanScottLewis/master

Slightly faster Array#each method.

mrblib/array.rb

@@ -10,11 +10,9 @@ class Array
   #
   # ISO 15.2.12.5.10
   def each(&block)
-    idx = 0
-    while(idx < length)
-      block.call(self[idx])
-      idx += 1
-    end
+    idx, length = -1, self.length-1
+    block.call(self[idx += 1]) while(idx < length)
+    
     self
   end