[expr.pre] Add \tcode for 5

Author: Andreas-Krug

source/expressions.tex

@@ -95,7 +95,7 @@
 \end{codeblock}
 due to the associativity and precedence of these operators. Thus, the
 result of the sum \tcode{(a + 32760)} is next added to \tcode{b}, and
-that result is then added to 5 which results in the value assigned to
+that result is then added to \tcode{5} which results in the value assigned to
 \tcode{a}. On a machine in which overflows produce an exception and in
 which the range of values representable by an \tcode{int} is
 \crange{-32768}{+32767}, the implementation cannot rewrite this