[Bug c/84298] Shared TYPE_SIZE_UNIT ends up with freed SSA names

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84298

--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Fri, 9 Feb 2018, rguenth at gcc dot gnu.org wrote:

> The fix is to place a DECL_EXPR somewhere by the FE.  We have some duplicates
> with similar issues.

Should c_fully_fold_internal then generate something involving a DECL_EXPR 
for C_MAYBE_CONST_EXPR, instead of just a COMPOUND_EXPR?  (In the general 
case where the size expression has side effects, it must be evaluated at 
that exact point in the expression, if and only if that point is reached 
in evaluation.)

(MOVED = bug filed in a different bug tracker for a different project.  
That's for e.g. something that's actually a binutils or glibc bug; I don't 
see how it applies here.)