Merge 2018-03 CWG Motion 3

Author: zygoloid

source/statements.tex

@@ -672,8 +672,8 @@
 \item if the \grammarterm{for-range-initializer} is an expression of
 class type \tcode{C}, the \grammarterm{unqualified-id}{s}
 \tcode{begin} and \tcode{end} are looked up in the scope of \tcode{C}
-as if by class member access lookup\iref{basic.lookup.classref}, and if either
-(or both) finds at least one declaration, \placeholder{begin-expr} and
+as if by class member access lookup\iref{basic.lookup.classref}, and if
+both find at least one declaration, \placeholder{begin-expr} and
 \placeholder{end-expr} are \tcode{__range.begin()} and \tcode{__range.end()},
 respectively;