armemu: Fix SXTAH

src/core/arm/interpreter/armemu.cpp

@@ -6057,7 +6057,8 @@ L_stm_s_takeabort:
 
 			return 1;
 		}
-		case 0x6b: {
+		case 0x6b:
+		{
 			ARMword Rm;
 			int ror = -1;
 
@@ -6088,7 +6089,7 @@ L_stm_s_takeabort:
 			if (ror == -1)
 				break;
 
-			Rm = ((state->Reg[BITS(0, 3)] >> ror) & 0xFFFF);
+			Rm = ((state->Reg[BITS(0, 3)] >> ror) & 0xFFFF) | ((state->Reg[BITS(0, 3)] << (32 - ror)) & 0xFFFF) & 0xFFFF;
 			if (Rm & 0x8000)
 				Rm |= 0xffff0000;