gimplify.c (gimplify_scalar_mode_aggregate_compare): New function.
* gimplify.c (gimplify_scalar_mode_aggregate_compare): New function.
(gimplify_expr): Use it for tcc_comparison of operands of non BLKmode
aggregate types.
* tree-ssa-loop-im.c (for_each_index): Handle ARRAY_RANGE_REF as
ARRAY_REF, so have the callback called for the low bound expression.
* gnat.dg/scalar_mode_agg_compare_loop.adb: New test.
* gnat.dg/scalar_mode_agg_compare.adb: New test.