integrate changes from ARM64 backend and more

- better handle LDM/STM in reg alloc
- unify Halted and IRQ in anticipation for branch inlining
- literal optimisations can be disabled in gui
- jit blocks follow simple returns
- fix idle loop detection
- break jit blocks on IRQ (fixes saving in Pokemon White)

src/ARM_InstrInfo.h

@@ -236,7 +236,7 @@ enum
 
 struct Info
 {
-    u16 DstRegs, SrcRegs;
+    u16 DstRegs, SrcRegs, NotStrictlyNeeded;
     u16 Kind;
 
     u8 SpecialKind;