update README & HACK with SystemZ information
diff --git a/HACK.TXT b/HACK.TXT
index 2462169..6e7f7ed 100644
--- a/HACK.TXT
+++ b/HACK.TXT
@@ -7,6 +7,8 @@
 │   ├── ARM         <- ARM engine
 │   ├── Mips        <- Mips engine
 │   ├── PowerPC     <- PowerPC engine
+│   ├── Sparc       <- Sparc engine
+│   ├── SystemZ     <- SystemZ engine
 │   └── X86         <- X86 engine
 ├── bindings        <- all bindings are under this dir
 │   ├── java        <- Java bindings + test code