Fix the UBSan inexpensive call sanitization

Fix the UBSan inexpensive call sanitization

The change imported in order to fix false positive -Wmaybe-uninitialized
in several packages in UBSan builds.

    * gimple.c: Include builtins.h
    (gimple_inexpensive_call_p): New function.
    * gimple.h (gimple_inexpensive_call_p): Declare.
    * tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Use it.
    * tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Likewise;
    fix formatting.

upstream hash: f18de397b1e0523fd840800399ec6ea21ec04af8
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@237172 138bc75d-0d04-0410-961f-82ee72b054a4

Authored-by: hubicka