[intro.abstract] Change example for unspecified behavior. (#1930)

Author: jensmaurer

source/intro.tex

@@ -493,8 +493,8 @@
 \pnum
 Certain other aspects and operations of the abstract machine are
 described in this document as unspecified (for example,
-evaluation of expressions in a \grammarterm{new-initializer} if the allocation
-function fails to allocate memory\iref{expr.new}). Where possible, this
+order of evaluation of arguments in a function call\iref{expr.call}).
+Where possible, this
 document defines a set of allowable behaviors. These
 define the nondeterministic aspects of the abstract machine. An instance
 of the abstract machine can thus have more than one possible execution