[diff.basic] Fix underfull hbox

Author: AlisdairM

source/compatibility.tex

@@ -2785,7 +2785,7 @@
 
 \diffref{basic.def}
 \change
-\Cpp{} does not have ``tentative definitions'' as in C.\\
+\Cpp{} does not have ``tentative definitions'' as in C.
 \begin{example}
 At file scope,
 \begin{codeblock}