8171371: Remove redundant type-arguments from generic method calls
Reviewed-by: jjg, rfield, mchung

8161708: javac, consider a different way to handle access code for operators
Reviewed-by: mcimadamore

8151223: String concatenation fails with implicit toString() on package-private class
Reviewed-by: mcimadamore, forax

8148483: JEP 280: Indify String Concatenation
Reviewed-by: psandoz, mcimadamore, igerasim, forax, plevart, vlivanov, ihse
Contributed-by: Aleksey Shipilev <aleksey.shipilev@oracle.com>, Remi Forax <forax@univ-mlv.fr>, Peter Levart <peter.levart@gmail.com>