Implement ut_realloc
lexyy.c, pars0lex.l:
  Start using ut_malloc, ut_free, ut_realloc in pars0lex.l and lexyy.c; mem_realloc was broken; eliminate possible memcpy(NULL, ..., 0) from string_append()


innobase/pars/pars0lex.l:
  Start using ut_malloc, ut_free, ut_realloc in pars0lex.l and lexyy.c; mem_realloc was broken; eliminate possible memcpy(NULL, ..., 0) from string_append()
innobase/pars/lexyy.c:
  Start using ut_malloc, ut_free, ut_realloc in pars0lex.l and lexyy.c; mem_realloc was broken; eliminate possible memcpy(NULL, ..., 0) from string_append()
innobase/ut/ut0mem.c:
  Implement ut_realloc
innobase/include/ut0mem.h:
  Implement ut_realloc