of the InnoDB SQL parser.

pars_is_string_type(): New function.  Returns TRUE iff mtype equals
DATA_VARCHAR, DATA_CHAR, DATA_FIXBINARY, or DATA_BINARY.

pars_resolve_func_data_type(): Replace checks for DATA_VARCHAR with
pars_is_string_type().  For example, the NAME column of SYS_INDEXES,
SYS_TABLES, and SYS_COLUMNS is of DATA_BINARY type, although it
contains a UTF-8 character string.  This affects the functions
TO_NUMBER, BINARY_TO_NUMBER, LENGTH, INSTR, and SUBSTR.