[diff.mods.to.headers] Fix overfull hbox caused by a change in section

number.

Author: zygoloid

source/compatibility.tex

@@ -1790,7 +1790,7 @@
 nor are the C headers themselves part of \Cpp.
 
 \pnum
-The headers \tcode{<ccomplex>}\indextext{\idxhdr{ccomplex}} (\ref{depr.ccomplex.syn})
+The \Cpp headers \tcode{<ccomplex>}\indextext{\idxhdr{ccomplex}} (\ref{depr.ccomplex.syn})
 and \tcode{<ctgmath>}\indextext{\idxhdr{ctgmath}} (\ref{depr.ctgmath.syn}), as well
 as their corresponding C headers \tcode{<complex.h>}\indextext{\idxhdr{complex.h}}
 and \tcode{<tgmath.h>}\indextext{\idxhdr{tgmath.h}}, do not contain any of the