gmacros: Provide platform-independent G_ALWAYS_INLINE and G_NO_INLINE
Coming from gobject-introspection!236 (diffs)
We had gcc-only implementation for no-inline, so I've firstly added a gcc only version for G_GNUC_ALWAYS_INLINE
(mostly for consistency, not sure if we want to skip the commit).
So, since we could create an independent version for them both, I've added also generic versions.
Edited by Marco Trevisan