libogc 1.8.24

• fix memset warning
• fix stat for latest newlib
• fix _SHIFTL macro usage (#76)
• Fix POLL* definitions per Dolphin (#73)
• Cleanup in audio.c (#72)
• gx: Fix definitions for GXMatrixType and swapped comments (#74)
• Fix random crash on thread exit
• Fix unlocked memory cards
• Fix multi-sector read
• Fix __gcsd_isInserted
• Fix __gcsd_startup