Start of adding code word support.

examples/code_x64.fs

@@ -0,0 +1,12 @@
+#! /usr/bin/env ueforth
+
+asm forth 
+
+code my2*
+  $48 code1, $89 code1, $f8 code1, ( mov %rdi, %rax )
+  $48 code1, $d1 code1, $27 code1, ( shlq [%rdi] )
+  $c3 code1,                       ( ret )
+end-code
+
+123 my2* . cr
+bye