Mark re-used phoneme_list as undefined

And fill the last phlist prepause and newword fields, otherwise they are
detected as undefined:

==483407== Conditional jump or move depends on uninitialised value(s)
==483407==    at 0x488E6AB: Generate (synthesize.c:1228)
==483407==    by 0x488FD94: SpeakNextClause (synthesize.c:1587)
==483407==    by 0x4887F56: Synthesize (speech.c:457)
==483407==    by 0x488884C: sync_espeak_Synth (speech.c:570)
==483407==    by 0x487B270: espeak_Synth (espeak_api.c:90)
==483407==    by 0x10ACA0: main (espeak-ng.c:691)
==483407==  Uninitialised value was created by a client request
==483407==    at 0x4884893: MakePhonemeList (phonemelist.c:155)
==483407==    by 0x4895712: TranslateClause (translate.c:2682)
==483407==    by 0x488FCCF: SpeakNextClause (synthesize.c:1569)
==483407==    by 0x4887F56: Synthesize (speech.c:457)
==483407==    by 0x488884C: sync_espeak_Synth (speech.c:570)
==483407==    by 0x487B270: espeak_Synth (espeak_api.c:90)
==483407==    by 0x10ACA0: main (espeak-ng.c:691)
==483407==
==483407== Conditional jump or move depends on uninitialised value(s)
==483407==    at 0x488E622: Generate (synthesize.c:1211)
==483407==    by 0x488FD94: SpeakNextClause (synthesize.c:1587)
==483407==    by 0x4887F56: Synthesize (speech.c:457)
==483407==    by 0x488884C: sync_espeak_Synth (speech.c:570)
==483407==    by 0x487B270: espeak_Synth (espeak_api.c:90)
==483407==    by 0x10ACA0: main (espeak-ng.c:691)
==483407==  Uninitialised value was created by a client request
==483407==    at 0x4884893: MakePhonemeList (phonemelist.c:155)
==483407==    by 0x4895712: TranslateClause (translate.c:2682)
==483407==    by 0x488FCCF: SpeakNextClause (synthesize.c:1569)
==483407==    by 0x4887F56: Synthesize (speech.c:457)
==483407==    by 0x488884C: sync_espeak_Synth (speech.c:570)
==483407==    by 0x487B270: espeak_Synth (espeak_api.c:90)
==483407==    by 0x10ACA0: main (espeak-ng.c:691)
==483407==

This is changing the ssml.test output, but with no audible difference,
so this is probably a real fix for it.

src/libespeak-ng/phonemelist.c

 #include "phoneme.h"
 #include "synthesize.h"
 #include "translate.h"
+#include "speech.h"
 
 const unsigned char pause_phonemes[8] = {
 	0, phonPAUSE_VSHORT, phonPAUSE_SHORT, phonPAUSE, phonPAUSE_LONG, phonGLOTTALSTOP, phonPAUSE_LONG, phonPAUSE_LONG
 	plist2 = ph_list2;
 	phlist = phoneme_list;
 	end_sourceix = plist2[n_ph_list2-1].sourceix;
+	MAKE_MEM_UNDEFINED(&phoneme_list, sizeof(phoneme_list));
 
 	// is the last word of the clause unstressed ?
 	max_stress = 0;
 	phlist[ix].length = post_pause; // length of the pause, depends on the punctuation
 	phlist[ix].sourceix = end_sourceix;
 	phlist[ix].synthflags = 0;
+	phlist[ix].prepause = 0;
 	phlist[ix++].ph = phoneme_tab[phonPAUSE];
 
+	phlist[ix].newword = 0;
+
 	phlist[ix].phcode = phonPAUSE;
 	phlist[ix].type = phPAUSE;
 	phlist[ix].length = 0;
 	phlist[ix].sourceix = 0;
 	phlist[ix].synthflags = 0;
+	phlist[ix].prepause = 0;
 	phlist[ix++].ph = phoneme_tab[phonPAUSE_SHORT];
 
 	n_phoneme_list = ix;

tests/ssml.test

 for i in `ls tests/ssml/*.ssml` ; do test_ssml $i; done
 for i in `ls tests/ssml/*.ssml2` ; do test_ssml $i punct; done
 
-test_ssml_audio "<prosody>" fcb28f00670959980038171ceda3c6bdec61b884 "<speak><prosody rate=\"x-slow\" pitch=\"low\"> Slow and low </prosody><prosody rate=\"x-fast\" pitch=\"x-high\"> Fast and high.</prosody></speak>"
+test_ssml_audio "<prosody>" 88fccb35536158f25f4ae44a03fb005fef95c99b "<speak><prosody rate=\"x-slow\" pitch=\"low\"> Slow and low </prosody><prosody rate=\"x-fast\" pitch=\"x-high\"> Fast and high.</prosody></speak>"
 # #410 is a bug in SSML. Sentence termination causes prosody stack to misfunction. 
-# Hash 00879af is the buggy version and should fail:
-test_ssml_audio "<prosody> bug #410" 00879aff11dc28a352736ca397ce9567e6f39029 "<speak><prosody rate=\"x-slow\" pitch=\"low\"> Slow and low. </prosody><prosody rate=\"x-fast\" pitch=\"x-high\"> Fast and high.</prosody></speak>"
+# Hash 8d3bace is the buggy version and should fail:
+test_ssml_audio "<prosody> bug #410" 8d3bace9548ae73c4770a73c88c6f65e848b45cf "<speak><prosody rate=\"x-slow\" pitch=\"low\"> Slow and low. </prosody><prosody rate=\"x-fast\" pitch=\"x-high\"> Fast and high.</prosody></speak>"
 test_ssml_audio "<audio>" 5134c1db757b2d6b8d1f3f2416124462e401b4c6 "<speak>ha: <audio src=\"$PWD/phsource/h/ha.wav\"></audio></speak>"