vcomp/cmpto_j2k.cpp - Update val comparison to DBL_MAX

[ATrivialAtomic]

This PR changes #define ASSIGN_CHECK_VAL(var, str, minval) to compare val > DBL_MAX instead of val > UINT_MAX.

This fixes an issue where, when mem_limit= exceeds 4.29G, the resulting return from unit_evaluate_dbl will exceed UINT_MAX limit and return an unexpected error.

[MartinPulec]

I got the point. I understand that for mem_limit, 4 GiB may not be sufficient in general.

But the comparison to DBL_MAX in doubles will be AFAIK almost always true (unless the val is INFINITY; maybe also some other special dbl values). As this particular check there is mainly not to overflow the destination type, wouldn't be better to compare to the maximal value of the dst type instead, eg. std::numeric_limits<typeof var>::max()?