manual close() with StackFrame

[jposwiata]

It is not possible to manually "close" StackFrame without passing makeEpilog arg to the constructor.
Pattern:

Xbyak::util::StackFrame sf(this, 1);
... some code ...
close();
readyRE();

causes exception, as second close() is forced from the destructor.
Is there any reason why close() doesn't check/clear makeEpilog_?
O/c "scoped" StackFrame object (closed in '{}' before readyRE() works fine.

[herumi]

I was using close() to mean makeEpilog().
That was misleading.
I call makeEpilog() multiple times when I want to return from multiple places in a function.

How about this commit?
3a823ad
though it breaks backward compatibility.