Memset MCInst to 0 on initialization.

Old modules (and possibly the new ones as well) are not built for none zeroed MCInst.
It leads again and again to segfaults or false disassembly.
So now it is fixed.

MCInst.c

@@ -18,6 +18,7 @@
 
 void MCInst_Init(MCInst *inst, cs_arch arch)
 {
+	memset(inst, 0, sizeof(MCInst));
 	// unnecessary to initialize in loop . its expensive and inst->size should be honored
 	inst->Operands[0].Kind = kInvalid;
 	inst->Operands[0].ImmVal = 0;