tree-optimization/116768 - wrong dependence analysis

tree-optimization/116768 - wrong dependence analysis

The following reverts a bogus fix done for PR101009 and instead makes
sure we get into the same_access_functions () case when computing
the distance vector for g[1] and g[1] where the constants ended up
having different types.  The generic code doesn't seem to handle
loop invariant dependences.  The special case gets us both
( 0 ) and ( 1 ) as distance vectors while formerly we got ( 1 ),
which the PR101009 fix changed to ( 0 ) with bad effects on other
cases as shown in this PR.

	PR tree-optimization/116768
	* tree-data-ref.cc (build_classic_dist_vector_1): Revert
	PR101009 change.
	* tree-chrec.cc (eq_evolutions_p): Make sure (sizetype)1
	and (int)1 compare equal.

	* gcc.dg/torture/pr116768.c: New testcase.

(cherry picked from commit 5b5a36b122e1205449f1512bf39521b669e713ef)