Fixed conversion of large uint/ulong/long hex literals

[gaschd]

Problem

#1147

Hex literals of numeric types uint, ulong and long with larger values than int.MaxValue failed to convert as there was a special case for int hex literals, where the numeric value is parsed to an int causing a wrong conversion.

Solution

Restricting this special case (8 digit hex literal) to values of type int only.

#1115 resolved issue #1064 for integer values but long hex literals (16 digit hex literal) seem to have the same issue:

0xFFFFFFFFFFFFFFFEL is interpreted as uint64 instead of int64.

So this PR also applies the same solution to convert

Private Const LargeLong As Long = &HFFFFFFFFFFFFFFFEL
to
private const long LargeLong = unchecked((long)0xFFFFFFFFFFFFFFFE);