Fixes #10846

Motivation / Problem

array(4611686018427387904) implies allocating 4611686018427387904 * 16 (size of SQObjectPtr) and that is 0 in 64bit world.
And as there is no check for overflow we happily allocate 0 bytes of memory and use it like if we allocated the expected number of elements.

Description

Check for overflow of newsize * sizeof(T) when reallocating sqvector.
As sqvector is deep inside squirrel we don't have access to the VM and the only way to signal the error is throwing an exception. The only catchable exception without adding special handling inside squirrel itself, SQVM catches ... and rethrows, is Script_FatalError so I used it.

Adding overflow check in https://github.com/OpenTTD/OpenTTD/blob/master/src/3rdparty/squirrel/squirrel/sqbaselib.cpp#L217 could work for array() but would not protect when resizing the array after its creation, like in

local x = array(10);
x.resize(4611686018427387904);

Limitations

Squirrel compiler also uses sqvector but it only catches SQChar *, so throwing something else might be an issue. Anyway compiler is less likely to try to allocate enough to trigger an overflow.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR touches english.txt or translations? Check the guidelines
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker