cpu: emulate AMD-only Zen 2 instructions in software (#449)

Handle immediate EXTRQ and INSERTQ as well as MONITORX and MWAITX when the host raises illegal-instruction faults. Add unit coverage for SSE4a bit-field semantics and preserve existing load-time patching.

Co-authored-by: zocomputer <help@zocomputer.com>

src/SharpEmu.Core/Cpu/Native/DirectExecutionBackend.Exceptions.cs

@@ -133,6 +133,11 @@ public sealed partial class DirectExecutionBackend
 			{
 				return -1;
 			}
+			if (exceptionCode == StatusIllegalInstruction &&
+				TryRecoverAmdCompatInstruction(contextRecord, rip))
+			{
+				return -1;
+			}
 			if (IsBenignHostDebugException(exceptionCode))
 			{
 				return -1;