[AArch64] Implement Fiora's preemptive paired loadstore optimization.

This provides a decent speed up in pretty much everything that touches pair loadstores because in most cases they are just regular non-quantizing
float loadstores that happen.

Source/Core/Core/PowerPC/JitArmCommon/BackPatch.h

@@ -9,17 +9,22 @@ struct BackPatchInfo
 {
 	enum
 	{
-		FLAG_STORE    = (1 << 0),
-		FLAG_LOAD     = (1 << 1),
-		FLAG_SIZE_8   = (1 << 2),
-		FLAG_SIZE_16  = (1 << 3),
-		FLAG_SIZE_32  = (1 << 4),
-		FLAG_SIZE_F32 = (1 << 5),
-		FLAG_SIZE_F64 = (1 << 6),
-		FLAG_REVERSE  = (1 << 7),
-		FLAG_EXTEND   = (1 << 8),
-		FLAG_SIZE_F32I = (1 << 9),
-		FLAG_ZERO_256  = (1 << 10),
+		FLAG_STORE      = (1 << 0),
+		FLAG_LOAD       = (1 << 1),
+		FLAG_SIZE_8     = (1 << 2),
+		FLAG_SIZE_16    = (1 << 3),
+		FLAG_SIZE_32    = (1 << 4),
+		FLAG_SIZE_F32   = (1 << 5),
+		FLAG_SIZE_F32X2 = (1 << 6),
+		FLAG_SIZE_F64   = (1 << 7),
+		FLAG_REVERSE    = (1 << 8),
+		FLAG_EXTEND     = (1 << 9),
+		FLAG_SIZE_F32I  = (1 << 10),
+		FLAG_ZERO_256   = (1 << 11),
+		FLAG_MASK_FLOAT = FLAG_SIZE_F32 |
+		                  FLAG_SIZE_F32X2 |
+		                  FLAG_SIZE_F64 |
+		                  FLAG_SIZE_F32I,
 	};
 
 	static u32 GetFlagSize(u32 flags)