[patch] support for temps of variable size with const upper bound

[Olivier Hainque]

Roger Sayle wrote:

> > 	(force_constant_size): New static function.
> > 	(gimple_add_tmp_var): Use it, forcing variable size to a
> > 	constant upper bound if it is not constant on entry.

> This is OK for mainline,

> Once again could you add the Ada "procedure P" testcase from your
> post above to the gnat testsuite, confirming that it ICEs the compiler
> without your change, but PASSes fine with it.

 Just did so and installed the changes. Thanks for your review.

 Olivier