Fixed missing function declaration

Without this function declaration, the build fails on modern C compilers (ISO C99). This affects e.g. builds on Apple Silicon. This fix is also needed in order to compile rasspy/piper on Apple silicon

src/libespeak-ng/translate.h

@@ -669,6 +669,7 @@ void print_dictionary_flags(unsigned int *flags, char *buf, int buf_len);
 
 int TranslateWord(Translator *tr, char *word1, WORD_TAB *wtab, char *word_out);
 void TranslateClause(Translator *tr, int *tone, char **voice_change);
+void TranslateClauseWithTerminator(Translator *tr, int *tone_out, char **voice_change, int *terminator_out);
 
 void SetVoiceStack(espeak_VOICE *v, const char *variant_name);