[project @ 2001-10-17 15:44:40 by simonpj]

[project @ 2001-10-17 15:44:40 by simonpj]
---------------------------
  	Better floating in CorePrep
  	---------------------------

	** DO NOT MERGE  **

[NB: this commit also changes the wrongly-named
	-ddump-sat
flag to be called
	-ddump-prep ]

Earlier fiddling with CorePrep meant that it was ANF-ing
the top-level defn:

	x = length [True,False]
to
	x = let	s1 = False : []
		s2 = True  : s1
	    in length s2

This is Very Bad for big constant data structures, as show
up in Happy-generated parsers, and that's why we get the
big-block-alloc crash in hssource.  Instead we want

	s1 = False : []
	s2 = True  : s1
	x = length s2

This happens now, (I hope), but it's part of an ongoing jiggling
process in the CoreTidy-CorePrep-CoreToStg part of the compiler, so
it's possible I have broken something else.