Add test for shift preserving flags

Signed-off-by: Paris Oplopoios <21157395+OFFTKP@users.noreply.github.com>

unittests/ASM/Flags/Shift.asm

@@ -0,0 +1,69 @@
+%ifdef CONFIG
+{
+  "RegData": {
+    "R12": "0x55",
+    "R13": "0x890",
+    "R14": "0x55"
+  }
+}
+%endif
+
+mov rsi, 0xe0000080
+mov rsp, 0xe0001000
+
+; Zero shift amount
+xor ecx, ecx
+
+; Zero all flags
+xor eax, eax
+push rax
+popfq
+
+mov r8b, 255
+mov r10b, 127
+mov r11b, 1
+
+
+add r8b, r11b ; Sets CF, ZF, PF, AF, zeroes OF, SF
+; Shift by zero, flags should be unaffected
+; This tests that we didn't optimize away the flag calculations of the add
+shl rax, cl
+
+; Ensure we can't predict the next block
+lea rdi, [rel .next]
+mov [rsi - 8], rdi
+jmp [rsi - 8]
+
+.next:
+pushfq
+pop r12
+
+; Mask with flags we care about
+and r12, 0x8d5
+
+add r10b, r11b ; Sets OF, SF, AF, zeroes ZF, CF, PF
+shr rax, cl
+
+lea rdi, [rel .next2]
+mov [rsi - 8], rdi
+jmp [rsi - 8]
+
+.next2:
+pushfq
+pop r13
+and r13, 0x8d5
+
+mov r8b, 255
+add r8b, r11b ; Sets CF, ZF, PF, AF, zeroes OF, SF
+sar rax, cl
+
+lea rdi, [rel .next3]
+mov [rsi - 8], rdi
+jmp [rsi - 8]
+
+.next3:
+pushfq
+pop r14
+and r14, 0x8d5
+
+hlt