Add check array out of bound.

Code for debugging const_value annotations in abstract syntax tree.

Fix 'overflow' detection for real64.

small bug fix.

Fix compare expression in constat folding class.

Fix extract_real (thanks Manuele), and add check for overflow.

cleaning up the code...

Fix remaining overflow checks.

remove incorrect include file.

Correctly implement MOD operation and overflow checks (still missing uint * / MOD).

Re-insert errno=0 before calling strtoXX() (thanks go to Manuele)

cosmetic changes.

Add data structure for storing overflow of constant values.

make the compiler platform independent (i.e. no longer assume sizeof(double)==8).