Don't call isspace and iscntrl in the validation hot path
Don't call isspace and iscntrl in the validation hot path

Summary: Because they are slow, don't get inlined, and require lookups in the locale table even though the keys are supposed to be ASCII.

Reviewed By: spalamarchuk

Differential Revision: D4113933

fbshipit-source-id: 88dac383c74797be1c521151b8fcfbff7e3f34a4

facebook/mcrouter,facebook/mcrouter,facebook/mcrouter,facebook/mcrouter