[google/4_7] Patch committed: backport the location_block bugfix patches from trunk

[Dehao Chen]

I have backported the following patches from trunk to google-4_7:

191931, 192049, 192120, 192165

gcc:
2012-10-08  Dehao Chen  <de...@google.com>

        Backport 191931, 192049, 192120, 192165 from trunk.

        * tree-vect-loop-manip.c (slpeel_make_loop_iterate_ntimes): Use
        LOCATION_LOCUS to compare with UNKNOWN_LOCATION.
        (slpeel_tree_peel_loop_to_edge): Likewise.
        * tree-vectorizer.c (vectorize_loops): Likewise.
        * tree-cfg.c (move_block_to_fn): Update lexical block for phi_args.
        * tree-ssa-live.c (clear_unused_block_pointer_1): Look at
        DECL_DEBUG_EXPR again.
        * gimple-low.c (lower_stmt): Set the block for call args.

testsuite:
2012-10-08  Dehao Chen  <de...@google.com>

        Backport r192049 from:trunk:

        * gcc.dg/pr54782.c: New test.

Bootstrapped and passed crosstool tests.

Dehao