Merge pull request rails#10627 from vipulnsward/destructive_symbolize

Change to destructive `deep_symbolize_keys` to avoid a new hash creation.

Author: carlosantoniodasilva

activesupport/lib/active_support/hash_with_indifferent_access.rb

@@ -224,7 +224,7 @@ def deep_stringify_keys; dup end
     undef :symbolize_keys!
     undef :deep_symbolize_keys!
     def symbolize_keys; to_hash.symbolize_keys! end
-    def deep_symbolize_keys; to_hash.deep_symbolize_keys end
+    def deep_symbolize_keys; to_hash.deep_symbolize_keys! end
     def to_options!; self end
 
     def select(*args, &block)