backport: re PR tree-optimization/91137 (Wrong code with -O3)

backport: re PR tree-optimization/91137 (Wrong code with -O3)

        Backport from mainline
        2019-07-18  Bin Cheng  <bin.linux@linux.alibaba.com>

        PR tree-optimization/91137
        * tree-ssa-loop-ivopts.c (struct ivopts_data): New field.
        (tree_ssa_iv_optimize_init, alloc_iv, tree_ssa_iv_optimize_finalize):
        Init, use and fini the above new field.
        (determine_base_object_1): New function.
        (determine_base_object): Reimplement using walk_tree.

gcc/testsuite
        2019-07-18  Bin Cheng  <bin.linux@linux.alibaba.com>

        PR tree-optimization/91137
        * gcc.c-torture/execute/pr91137.c: New test.

From-SVN: r273754