libstdc++: Remove <debug/array>

libstdc++: Remove <debug/array>

Add _GLIBCXX_ASSERTIONS assert in normal std::array and remove __gnu_debug::array
implementation.

libstdc++-v3/ChangeLog:

	* include/debug/array: Remove.
	* include/Makefile.am: Remove <debug/array>.
	* include/Makefile.in: Regenerate.
	* include/experimental/functional: Adapt.
	* include/std/array: Move to _GLIBCXX_INLINE_VERSION namespace.
	* include/std/functional: Adapt.
	* include/std/span: Adapt.
	* testsuite/23_containers/array/debug/back1_neg.cc:
	Remove dg-require-debug-mode. Add -D_GLIBCXX_ASSERTIONS option.
	* testsuite/23_containers/array/debug/back2_neg.cc: Likewise.
	* testsuite/23_containers/array/debug/front1_neg.cc: Likewise.
	* testsuite/23_containers/array/debug/front2_neg.cc: Likewise.
	* testsuite/23_containers/array/debug/square_brackets_operator1_neg.cc:
	Likewise.
	* testsuite/23_containers/array/debug/square_brackets_operator2_neg.cc:
	Likewise.
	* testsuite/23_containers/array/element_access/60497.cc
	* testsuite/23_containers/array/tuple_interface/get_debug_neg.cc:
	Remove.
	* testsuite/23_containers/array/tuple_interface/get_neg.cc
	* testsuite/23_containers/array/tuple_interface/tuple_element_debug_neg.cc
	* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc