CRASH_COND should assert, not just log and return

When porting code from a module, I noticed the `CRASH_COND` macro in C++ bindings does not actually behave like an assert, but does log something (only with the "FATAL" prefix) and continues execution.

I believe this isn't the intention of this macro, which would otherwise need a variant with value to return... but anyways, I think it should really crash by generating a trap after logging the error, like Godot does.