Spring Add fast-path for no-args constructor in BeanUtils.instantiateClass

For the cases when constructor has no args we could have fast-paths which is likely to improve start-up time as BeanUtils.instantiateClass is called at least once for each bean instantiation in application context.

Comment From: stsypanov

@sdeleuze Could you have a look into this?

Comment From: stsypanov

@sdeleuze is there anything I could do about this PR?