* dependency.c (gfc_dep_compare_expr): Strip parentheses and unary

	* dependency.c (gfc_dep_compare_expr): Strip parentheses and unary
	plus operators when comparing expressions.  Handle comparisons of
	the form "X+C vs. X", "X vs. X+C", "X-C vs. X" and "X vs. X-C" where
	C is an integer constant.  Handle comparisons of the form "P+Q vs.
	R+S" and "P-Q vs. R-S".  Handle comparisons of integral extensions
	specially (increasing functions) so extend(A) > extend(B), when A>B.
	(gfc_check_element_vs_element): Move test later, so that we ignore
	the fact that "A < B" or "A > B" when A or B contains a forall index.

	* gfortran.dg/dependency_14.f90: New test case.
	* gfortran.dg/dependency_15.f90: Likewise.
	* gfortran.dg/dependency_16.f90: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@112605 138bc75d-0d04-0410-961f-82ee72b054a4