data(kana): Mozc's romaji table

hira.map and kata.map knew 152 keys of the 320 every Japanese IME
accepts: no nn, no small kana by x or l (xtu, xya, la, ...), no sya, tya,
zya, jya, dya, cya, tsa, thi, dhi, twu, kye, ye, fya, wha, and zi gave ぢ.
Both are now Mozc's default table in full, kata.map in Katakana, so that
they agree (kata.map alone had di → ディ and a lone v).  With Mozc, wi
and we are うぃ and うぇ (wyi and wye the old kana), the v row is ゔ, nn
is ん, and [ ] ~ and the z-prefixed symbols type 「 」 〜 ・ … ← ↓ ↑ →.

n' is a row now, not a case in transjp.  A row whose value is っ keeps
its consonant pending only when it is a doubled consonant or tch: xtu
and ltu are っ itself, so a lone っ can finally be typed.

strans.c

@@ -285,10 +285,15 @@ backjp(Im *p)
 		spopr(&p->pre);
 }
 
+/*
+ * kk and the like are a sokuon: っ, and the consonant stays pending, as
+ * ch does after tch.  xtu and ltu are っ itself.
+ */
 static int
-issmalltsu(Str *s)
+issokuon(Str *key, Str *mapped)
 {
-	return s->n == 1 && (s->r[0] == L'っ' || s->r[0] == L'ッ');
+	return mapped->n == 1 && (mapped->r[0] == L'っ' || mapped->r[0] == L'ッ') &&
+		(key->r[0] == key->r[1] || (key->r[0] == 't' && key->r[1] == 'c'));
 }
 
 static void
@@ -312,17 +317,11 @@ transjp(Im *p, Rune c)
 	e.eat = 1;
 	e.next = p->pre;
 	e.raw = p->raw;
-	if(c == '\'' && e.raw.n == 1 && e.raw.r[0] == 'n'){
-		if(mapget(p->l->map, &e.raw, &mapped))
-			sappend(&e.next, &mapped);
-		sclear(&e.raw);
-		return e;
-	}
 	key = e.raw;
 	sputr(&key, c);
 	if(mapmatch(p->l->map, &key, &mapped) != TrieMiss){
 		e.raw = key;
-		if(issmalltsu(&mapped)){
+		if(issokuon(&key, &mapped)){
 			sappend(&e.next, &mapped);
 			keeptail(&e.raw);
 		}