I fell over an ICE where wide_int_to_type_1's expectations of pointer
value caching didn't match that of cache_integer_cst's behaviour. I
don't know why it only exhibited on the modules branch, but it seems
pretty wrong. This patch matches up the behaviours and adds a comment
about that.
gcc/
* tree.c (cache_integer_cst): Fixup pointer caching to match
wide_int_to_type_1's expectations. Add comment.