Replace uses of VLAs (variable-length arrays) using g_newa(), since
Visual Studio builds will unlikely ever support VLAs (which became optional
in C11).
https://bugzilla.gnome.org/show_bug.cgi?id=773299
Little tool that creates a bunch of test files to throw add the
rendernode binary.
They should really be part of a testsuite, but we have none, so OI just
put them here.