engine: romaji is case-blind

Shift or Caps Lock made a Japanese key pass through as a Latin capital,
so nothing composed with Caps Lock on; Korean already folds case. Latin
text still has Ctrl+T.

tests/engine_test.c

@@ -1182,6 +1182,14 @@ engine_japanese_backspace_and_boundaries(struct ct *t)
 		CT_CHECK(t, keystroke(' ', 0, &com));
 		checkstr(t, "real input boundary", "かんじ ", &com);
 	}
+
+	init();
+	im.l = getlang(LangJP);
+	sclear(&com);
+	if(typekeys(t, "KA", &com)){
+		impre(&im, &shown);
+		checkstr(t, "uppercase romaji", "か", &shown);
+	}
 }
 
 void