[diff.cpp14.lex] Update 'basic source' to 'translation' character set

Author: jensmaurer

source/compatibility.tex

@@ -786,8 +786,8 @@
 semantics in this revision of \Cpp{}. Implementations may choose to
 translate trigraphs as specified in \CppXIV{} if they appear outside of a raw
 string literal, as part of the \impldef{mapping from physical source file characters
-to basic source character set} mapping from physical source file characters to
-the basic source character set.
+to translation character set} mapping from physical source file characters to
+the translation character set.
 
 \diffref{lex.ppnumber}
 \change