Provide internal open() function.
Provide internal open() function.

This is for the benefit of static versions of Compile and Check functions,
so they do not load anything in advance i.e. custom Magic databases etc ...

Signed-off-by: Krzysztof Wilczynski <9bf091559fc98493329f7d619638c79e91ccf029@linux.com>

kwilczynski/go-magic,kwilczynski/go-magic,kwilczynski/go-magic