[expr] Add cross-references for 'local entity'.

A local entity is not any entity that is local, so add
cross-references for clarification.

Author: jensmaurer

source/expressions.tex

@@ -1442,7 +1442,7 @@
 \pnum
 The result is the entity denoted by
 the \grammarterm{unqualified-id}\iref{basic.lookup.unqual}.
-If the entity is a local entity
+If the entity is a local entity\iref{basic.pre}
 and naming it from outside of an unevaluated operand
 within the scope where the \grammarterm{unqualified-id} appears
 would result in some intervening \grammarterm{lambda-expression}
@@ -2125,7 +2125,7 @@
 
 \pnum
 The \grammarterm{identifier} in a \grammarterm{simple-capture}
-shall denote a local entity\iref{basic.lookup.unqual}.
+shall denote a local entity (\ref{basic.lookup.unqual}, \ref{basic.pre}).
 The \grammarterm{simple-capture}{s} \keyword{this} and \tcode{* \keyword{this}}
 denote the local entity \tcode{*\keyword{this}}.
 An entity that is designated by a