Merge pull request #4813 from Sonicadvance1/movsxd_test

unittests: Adds missing movsxd edge case

unittests/ASM/Primary/Primary_63_2.asm

@@ -0,0 +1,27 @@
+%ifdef CONFIG
+{
+  "RegData": {
+    "RAX": "0xffffffff81828384",
+    "RBX": "0xffffffff81828384",
+    "RCX": "0x0000000081828384",
+    "RDX": "0x4142434445468384"
+  }
+}
+%endif
+
+mov rax, 0x4142434445464748
+mov rbx, 0x4142434445464748
+mov rcx, 0x4142434445464748
+mov rdx, 0x4142434445464748
+mov rsp, 0x6666666681828384
+
+; Default: 0x48, 0x63, 0xc4
+movsxd rax, esp
+; Default with o16 prefix: 0x66, 0x48, 0x63, 0xc4
+o16 movsxd rbx, esp
+; No-rex widening prefix
+db 0x63, 0xcc ; movsxd ecx, esp
+; o16 prefix with no-rex widening
+db 0x66, 0x63, 0xd4 ; movsxd dx, sp
+
+hlt