cleanup: move n_tunes and tunes to where they are used

src/libespeak-ng/intonation.c

 	{ PITCHfall,   70, 18, PITCHfall,   70, 24, NULL, 32, 20, 0 },      // 12 test
 };
 
-int n_tunes = 0;
-TUNE *tunes = NULL;
-
 #define SECONDARY        3
 #define PRIMARY          4
 #define PRIMARY_STRESSED 6

src/libespeak-ng/synthdata.c

 #include "translate.h"                // for Translator, LANGUAGE_OPTIONS
 #include "voice.h"                    // for ReadTonePoints, tone_points, voice
 
+int n_tunes = 0;
+TUNE *tunes = NULL;
+
 const int version_phdata  = 0x014801;
 
 // copy the current phoneme table into here

src/libespeak-ng/synthdata.h

 void SelectPhonemeTable(int number);
 int  SelectPhonemeTableName(const char *name);
 
+extern int n_tunes;
+extern TUNE *tunes;
+
 #ifdef __cplusplus
 }
 #endif

src/libespeak-ng/synthesize.h

 	int spare2; // the struct length should be a multiple of 4 bytes
 } TUNE;
 
-extern int n_tunes;
-extern TUNE *tunes;
+
 
 // phoneme table
 extern PHONEME_TAB *phoneme_tab[N_PHONEME_TAB];