In the 6.10 branch, show (toConstr 'A') == "A" while in the HEAD it is
"'A'".

due to "Do not print anything to stdout when stopping at a breakpoint with custom code"

On SPARC and PPC, double2Int (2^33) does a saturating conversion 
which results in 2147483647. 
On i386 it gives -2147483648, but I'm declaring that broken.