[basic.def] Better link do defintion of declaration (cplusplus#8191)

The plain text term in this sentence refer to the definition in [basic.pre]
and not the grammar production defined in [dcl].

Author: AlisdairM

source/basic.tex

@@ -164,7 +164,7 @@
 \indextext{declaration!definition versus}%
 \indextext{declaration}%
 \indextext{declaration!name}%
-A declaration\iref{dcl} may (re)introduce
+A declaration\iref{basic.pre} may (re)introduce
 one or more names and/or entities into a translation
 unit.
 If so, the