* tree.c (max_int_size_in_bytes): New function, inspired from
code in function.c:assign_temp.
* tree.h (max_int_size_in_bytes): Declare.
* function.c (assign_temp): Use it.
* gimplify.c (create_tmp_var): Relax the assertions on the type
properties, not mandating constant size any more.
(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.
* ada/misc.c (gnat_type_max_size): Look at TYPE_ADA_SIZE if we have
not been able to get a constant upper bound from TYPE_SIZE_UNIT.
* gnat.dg/varsize_temp.adb: New test.
From-SVN: r114938
