PS2OS: - Don't switch threads when interrupts are disabled. - Implemented iChangeThreadPriority.
PS2OS:
- Don't switch threads when interrupts are disabled.
- Implemented iChangeThreadPriority.

git-svn-id: 2ccb1f8d9e6dc8a19c79d6424fab741c5d5caced@806 b36208d7-6611-0410-8bec-b1987f11c4a2

LinkofHyrule89/Play-,AbandonedCart/Play-,Flav900/Play-,Alloyed/Play-,LinkofHyrule89/Play-,dragon788/Play-,AbandonedCart/Play-,AbandonedCart/Play-,Alloyed/Play-,dragon788/Play-,AbandonedCart/Play-,Flav900/Play-,dragon788/Play-,Flav900/Play-,Alloyed/Play-,Flav900/Play-,Alloyed/Play-,dragon788/Play-,AbandonedCart/Play-,dragon788/Play-,Flav900/Play-,LinkofHyrule89/Play-,Alloyed/Play-,LinkofHyrule89/Play-,LinkofHyrule89/Play-