CWG2287 Pointer-interconvertibility in non-standard-layout unions

Also revert "[class.union] Only standard-layout unions are
pointer-interconvertible" (0611331) which editorially resolved the same
confilct between the non-normative and normative wording in the opposite
direction, by changing the non-normative wording to match the normative
wording.

Author: Dawn Perchik

source/basic.tex

@@ -4064,7 +4064,7 @@
 \item
 they are the same object, or
 \item
-one is a standard-layout union object and
+one is a union object and
 the other is a non-static data member of that object~(\ref{class.union}), or
 \item
 one is a standard-layout class object and

source/classes.tex

@@ -1526,9 +1526,9 @@
 of its non-static data members. Each non-static data member is allocated
 as if it were the sole member of a struct.
 \begin{note}
-A standard-layout union object and its non-static data members are
+A union object and its non-static data members are
 pointer-interconvertible~(\ref{basic.compound}, \ref{expr.static.cast}).
-As a consequence, all non-static data members of such a
+As a consequence, all non-static data members of a
 union object have the same address.
 \end{note}