RFR/RFC (M) 7902575: Various code cleanups

[Aleksey Shipilev]

Hi there,

I am doing this cleanup in JMH code:
  https://bugs.openjdk.java.net/browse/CODETOOLS-7902575

...and while it should be safe, I would appreciate another pair of eyes to look through those:
  https://cr.openjdk.java.net/~shade/7902575/webrev.01/

Testing: jdk{7,8} x {annprocess,asm,reflection}

-- 
Thanks,
-Aleksey