function ReAllocMem(var p:pointer;Size:Longint):pointer;
Description:
ReAllocMem resizes the memory pointed to by P so it has size Size. The value of P may
change during this operation. The contents of the memory pointed to by P (if any) will
be copied to the new location, but may be truncated if the newly allocated memory block
is smaller in size. If a larger block is allocated, only the used memory is initialized, extra
memory will not be zeroed out.
Note that P may be nil, in that case the behaviour of ReAllocMem is equivalent to Getmem
(506).
Errors:
If no memory is available then a run-time error will occur.