core: Synchronize tree-cst & wide-int caching expectations

[Nathan Sidwell]

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.

pushing to trunk

nathan
-- 
Nathan Sidwell
-------------- next part --------------
A non-text attachment was scrubbed...
Name: cache-integer.diff
Type: text/x-patch
Size: 697 bytes
Desc: not available
URL: <https://gcc.gnu.org/pipermail/gcc-patches/attachments/20201102/d884c48f/attachment.bin>