fts_is_charset_cjk(): Avoid referencing global symbols

References to global symbols prevent InnoDB from being built as a
dynamic plugin on Windows.

Refer to CHARSET_INFO::number, because that is what InnoDB is already
persistently storing in its data dictionary.

storage/innobase/include/fts0types.ic

@@ -108,19 +108,21 @@ innobase_strnxfrm(
 @param[in]	cs	charset
 @retval	true	if the charset is cjk
 @retval	false	if not. */
-UNIV_INLINE
-bool
-fts_is_charset_cjk(
-	const CHARSET_INFO*	cs)
+inline bool fts_is_charset_cjk(const CHARSET_INFO* cs)
 {
-	return cs == &my_charset_gb2312_chinese_ci
-		|| cs == &my_charset_gbk_chinese_ci
-		|| cs == &my_charset_big5_chinese_ci
-		|| cs == &my_charset_ujis_japanese_ci
-		|| cs == &my_charset_sjis_japanese_ci
-		|| cs == &my_charset_cp932_japanese_ci
-		|| cs == &my_charset_eucjpms_japanese_ci
-		|| cs == &my_charset_euckr_korean_ci;
+	switch (cs->number) {
+	case 24: /* my_charset_gb2312_chinese_ci */
+	case 28: /* my_charset_gbk_chinese_ci */
+	case 1: /* my_charset_big5_chinese_ci */
+	case 12: /* my_charset_ujis_japanese_ci */
+	case 13: /* my_charset_sjis_japanese_ci */
+	case 95: /* my_charset_cp932_japanese_ci */
+	case 97: /* my_charset_eucjpms_japanese_ci */
+	case 19: /* my_charset_euckr_korean_ci */
+		return true;
+	default:
+		return false;
+	}
 }
 
 /** Select the FTS auxiliary index for the given character by range.