unittests: Adds ptest unit test to ensure correct flag setting

ptest wasn't correctly setting OF, SF, AF, and PF to zero until now.
Do a unit test to ensure correct behaviour here

unittests/ASM/H0F38/66_17_2.asm

@@ -0,0 +1,32 @@
+%ifdef CONFIG
+{
+  "RegData": {
+    "RAX": "0xFFFFFFFFFFFF43FF",
+    "RBX": "0"
+  }
+}
+%endif
+
+; Set EFLAGS to known value with sahf
+mov rax, -1
+sahf
+
+movups xmm0, [rel .data]
+; Tests a bug that FEX had where ptest would not set OF, SF, AF, PF to zero
+ptest xmm0, xmm0
+
+; Now load back
+; ZF = 1
+; CF = 1
+; OF, SF, AF, PF should be zero
+lahf
+
+; lahf doesn't get OF, get it with seto
+mov rbx, 0
+seto bl
+
+hlt
+
+.data:
+dq 0
+dq 0