[expr.prim.lambda] Add index entry for example of *this capture.

Author: zygoloid

source/expressions.tex

@@ -1065,6 +1065,7 @@
 \grammarterm{lambda-expression} captures an entity and that entity is not defined or
 captured in the immediately enclosing lambda expression or function, the program is
 ill-formed. \enterexample
+\indextext{Bond!James Bond}%
 \begin{codeblock}
 void f1(int i) {
   int const N = 20;