In the InnoDB internal SQL parser, there is the keyword
DOES_NOT_FIT_IN_MEMORY that is never specified in any CREATE TABLE
statement that is passed to the InnoDB SQL parser
(que_eval_sql() or pars_sql() or yyparse()). If this keyword were
ever present, it would set the flag dict_table_t::does_not_fit_in_memory
which is only present in debug builds.

Let us remove all traces of this.

Also, fix storage/innobase/pars/make_flex.sh so that no the generated
file storage/innobase/pars/lexyy.cc works as is.

FIXME: Always generate the InnoDB Bison files at build time, similar
to how sql/sql_yacc.yy is handled. (This would still leave the
generated scanner files, unless we want to add a build-time dependency
for Flex.)