PR27221, 058430b4 warnings while assembling the Linux kernel

	PR 27221
	* dwarf2dbg.c (dwarf2_gen_line_info_1): Don't warn about ignored
	line number info when gas is generating it.
	* testsuite/gas/elf/dwarf2-20.d: Adjust to not expect warnings.
	* testsuite/gas/m68hc11/indexed12.d: Likewise.
	* testsuite/gas/elf/elf.exp: Don't run warn-2.
	* gas/testsuite/gas/elf/warn-2.s: Delete.

(cherry picked from commit be07043e)