[Bug tree-optimization/110531] Vect: slp_done_for_suggested_uf is not initialized in tree-vect-loop.cc

["hliu at amperecomputing dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110531

--- Comment #10 from Hao Liu <hliu at amperecomputing dot com> ---
> foo is just an example for not getting inlined, the point here is extra cost paid.

My point is that the case is different from the original case in
tree-vect-loop.cc.  For example, change the case as following:

__attribute__((noipa)) int foo(int *a) { *a == 1 ? return 1 : return 0;}

That's similar to the original problem (the value of "a" is undefiend).

I don't mean that "a" must be initialized in test().  We can also initalize "a"
in foo, but should not use "a" before initialization. E.g.

__attribute__((noipa)) int foo(int *a) { 
  *a == 1;
  ...
  if (*a)
}

The above case has no problem.