Frees the memory pointed to by
mem.
If you know the allocated size of
mem, calling
freeSized may be faster, depending on the libc implementation
in use.
Starting from GLib 2.78, this may happen automatically in case a GCC
compatible compiler is used with some optimization level and the
allocated size is known at compile time (see
<
https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
documentation of `__builtin_object_size()`> to understand its
caveats).
If
mem is
Nothing it simply returns, so there
is no need to check
mem against
Nothing before
calling this function.