Grep slightly faster than select =~

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5546 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/lib/active_support/core_ext/exception.rb

@@ -28,6 +28,6 @@ class Exception # :nodoc:
   end
   
   def framework_backtrace
-    clean_backtrace.select {|line| line =~ FrameworkRegexp}
+    clean_backtrace.grep FrameworkRegexp
   end
-end
+end