tr_languages.c: Fix -Wmissing-prototypes warnings.

src/libespeak-ng/tr_languages.c

 	SetLetterBits(tr, LETTERGP_VOWEL2, (char *)ru_vowels);
 }
 
-void SetIndicLetters(Translator *tr)
+static void SetIndicLetters(Translator *tr)
 {
 	// Set letter types for Indic scripts, Devanagari, Tamill, etc
 	static const char dev_consonants2[] = { 0x02, 0x03, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x7b, 0x7c, 0x7e, 0x7f, 0 };
 	tr->langopts.suffix_add_e = tr->letter_bits_offset + 0x4d; // virama
 }
 
-void SetupTranslator(Translator *tr, const short *lengths, const unsigned char *amps)
+static void SetupTranslator(Translator *tr, const short *lengths, const unsigned char *amps)
 {
 	if (lengths != NULL)
 		memcpy(tr->stress_lengths, lengths, sizeof(tr->stress_lengths));