Regress test for SHR/SHL/SAR/SAL

This test needs to be checked for correctness.

suite/regress/x86_shifts.py

@@ -0,0 +1,24 @@
+#!/usr/bin/python
+
+# Github issue: #201
+# Author: fvrmatteo
+# Description: missing instructions SHR/SHL/SAR/SAL
+
+from keystone import *
+
+import regress
+
+class TestX86(regress.RegressTest):
+    def runTest(self):
+        # Initialize Keystone engine
+        ks = Ks(KS_ARCH_X86, KS_MODE_32)
+        # Assemble to get back insn encoding & statement count
+        encoding1, _ = ks.asm(b"shr eax, 1")
+        encoding2, _ = ks.asm(b"shl dword ptr ss:[esp], 2")
+        encoding3, _ = ks.asm(b"sar dword ptr ss:[0x10000000], 3")
+        self.assertEqual(encoding1, [ 0xd1, 0xe8 ])
+        self.assertEqual(encoding2, [ 0xc1, 0x24, 0x24, 0x02 ])
+        self.assertEqual(encoding3, [ 0x36, 0xc1, 0x3d, 0x00, 0x00, 0x00, 0x10, 0x03 ])
+
+if __name__ == '__main__':
+    regress.main()