Mark static arrays undefined when they are reused

So valgrind can potentially catch e.g. missing \0.

src/libespeak-ng/compiledict.c

 	char suffix[20];
 	static char output[80];
 
+	MAKE_MEM_UNDEFINED(&output, sizeof(output));
+
 	static const char symbols[] = {
 		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
 		'&', '%', '+', '#', 'S', 'D', 'Z', 'A', 'L', '!',

src/libespeak-ng/dictionary.c

 	char word[N_WORD_BYTES];
 	static char word_replacement[N_WORD_BYTES];
 
+	MAKE_MEM_UNDEFINED(&word_replacement, sizeof(word_replacement));
+
 	length = 0;
 	word2 = word1 = *wordptr;
 

src/libespeak-ng/readclause.c

 	static char buf[5];
 	char *p;
 
+	MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
+
 	p = buf;
 	for (ix = 3; ix >= 0; ix--) {
 		if ((*p = word >> (ix*8)) != 0)
 	char *string;
 	static char buf[60];
 
+	MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
+
 	buf[0] = 0;
 	flags[0] = 0;
 	flags[1] = 0;
 		c1 = c2;
 
 		if (ungot_string_ix >= 0) {
-			if (ungot_string[ungot_string_ix] == 0)
+			if (ungot_string[ungot_string_ix] == 0) {
+				MAKE_MEM_UNDEFINED(&ungot_string, sizeof(ungot_string));
 				ungot_string_ix = -1;
+			}
 		}
 
 		if ((ungot_string_ix == 0) && (ungot_char2 == 0))

src/libespeak-ng/ssml.c

 #include "synthesize.h"           // for SPEED_FACTORS, speed
 #include "translate.h"            // for CTRL_EMBEDDED, IsDigit09, utf8_out
 #include "voice.h"                // for SelectVoice, SelectVoiceByName
+#include "speech.h"               // for MAKE_MEM_UNDEFINED
 
 static const MNEM_TAB ssmltags[] = {
 	{ "speak",     SSML_SPEAK },
 	char language[40];
 	char buf[80];
 
+	MAKE_MEM_UNDEFINED(&voice_name, sizeof(voice_name));
+
 	strcpy(voice_name, ssml_stack[0].voice_name);
 	strcpy(language, ssml_stack[0].language);
 	voice_select.age = ssml_stack[0].voice_age;

src/libespeak-ng/synth_mbrola.c

 	char buf[50];
 	static char output[50];
 
+	MAKE_MEM_UNDEFINED(&output, sizeof(output));
+
 	output[0] = 0;
 	pitch_env = envelope_data[env];
 

src/libespeak-ng/synthdata.c

 	frame_t *frame;
 	static frameref_t frames_buf[N_SEQ_FRAMES];
 
+	MAKE_MEM_UNDEFINED(&frames_buf, sizeof(frames_buf));
+
 	seq = (SPECT_SEQ *)(&phondata_ptr[fmt_params->fmt_addr]);
 	seqk = (SPECT_SEQK *)seq;
 	nf = seq->n_frames;

src/libespeak-ng/synthesize.c

 #include "translate.h"            // for translator, LANGUAGE_OPTIONS, Trans...
 #include "voice.h"                // for voice_t, voice, LoadVoiceVariant
 #include "wavegen.h"              // for WcmdqInc, WcmdqFree, WcmdqStop
+#include "speech.h"               // for MAKE_MEM_UNDEFINED
 
 static void SmoothSpect(void);
 
 	int ix;
 	static char buf[5];
 
+	MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
+
 	for (ix = 0; ix < 4; ix++)
 		buf[ix] = word >> (ix*8);
 	buf[4] = 0;
 	ix++;
 	if (ix >= N_FRAME_POOL)
 		ix = 0;
+
+	MAKE_MEM_UNDEFINED(&frame_pool[ix], sizeof(frame_pool[ix]));
 	return &frame_pool[ix];
 }
 

src/libespeak-ng/translate.c

 	if (tr == NULL)
 		return;
 
+	MAKE_MEM_UNDEFINED(&voice_change_name, sizeof(voice_change_name));
+
 	embedded_ix = 0;
 	embedded_read = 0;
 	pre_pause = 0;

src/libespeak-ng/voices.c

 	static char variant_name[40];
 	char variant_prefix[5];
 
+	MAKE_MEM_UNDEFINED(&variant_name, sizeof(variant_name));
 	variant_name[0] = 0;
 	sprintf(variant_prefix, "!v%c", PATHSEP);
 	if (add_dir == 0)
 	static espeak_VOICE voice_variants[N_VOICE_VARIANTS];
 	static char voice_id[50];
 
+	MAKE_MEM_UNDEFINED(&voice_variants, sizeof(voice_variants));
+	MAKE_MEM_UNDEFINED(&voice_id, sizeof(voice_id));
+
 	*found = 1;
 	memcpy(&voice_select2, voice_select, sizeof(voice_select2));
 
 		// no language is specified. Get language from the named voice
 		static char buf[60];
 
+		MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
+
 		if (voice_select2.name == NULL) {
 			if ((voice_select2.name = voice_select2.identifier) == NULL)
 				voice_select2.name = ESPEAKNG_DEFAULT_VOICE;