The following seq# code should only be used in unoptimized code.
Be warned: it's a potential bug-farm.
+[SOF 8/98:
+ Yes, it completely fails to work for function values, since a PAP
+ closure will be constructed when the arg satisfaction check fails.
+ This PAP closure will add the magic values that gets pushed on the B stack
+ before entering the 'seqee' (new word!), as Jim is just about to tell
+ us about. Let's hear what he's got to say:
+]
First we push two words on the B stack: the current value of RetReg
(which may or may not be live), and a continuation snatched largely out
RetReg is restored, and we jump to the continuation, completing the
primop and going on our merry way.
+[ To workaround the shortcoming of not being able to deal with partially
+ applied values, we explicitly prohibit this at the Haskell source level
+ (i.e., we don't define an Eval instance for (->) ).
+]
+
\begin{code}
ED_RO_(vtbl_seq);