[fpc-pascal] Division by Zero - not raised exception

[Sasa Zeman]

> We don't consider this as a bug, it's for delphi compatibility reasons.
> These expressions are evaluated at compile time, so it's something
> differnt. If you want to get an error, compile with -Cr.

The -Cr will point on error in the code, however, enabling range checking
will also affect on global speed performance.

Definition in documentation (RTL.pdf):
"
29.20 EDivByZero
29.20.1 Description
EDivByZero is used when the operating system or CPU signals a division by
zero error.
"
As defined, reported issue is a bug. As well globaly, in consistency terms.

Far I can see, the core of the problem is in definiton of Infinity constant
as 1.0/0.0 and NaN with ln(-1.0) or 0.0/0.0 Perhaps this is necessary to
avoid problem with probably difference between different CPU/FPUs. However,
IEEE specification should be followed by all of them and bits manipulation
to perform infinity should be enough, instead to calculate it (as is
performed currently).