PR21287, Inconsistent section type for .init_array and .init_array.42

PR21287, Inconsistent section type for .init_array and .init_array.42

PR21287 notes that .init_array is correctly given a type of
SHT_INIT_ARRAY while .init_array.nnn gets SHT_PROGBITS.  This patch
fixes that problem, and properly drops warnings from the compiler that
would cause the testsuite to fail.  My a44d0bd78 change to check
ld_compile status, necessary to pick up compile errors, also meant
warnings were not ignored.

bfd/
	PR 21287
	* elf.c (special_sections_f): Match .fini_array and .fini_array.*.
	(special_sections_i): Likewise for .init_array.
	(special_sections_p): Likewise for .preinit_array.
ld/
	PR 21287
	* testsuite/ld-elf/init-fini-arrays.d: Match INIT_ARRAY and FINI_ARRAY.
	* testsuite/ld-elf/init-fini-arrays.s: Use %init_array and %fini_array
	section types.
	* testsuite/lib/ld-lib.exp (default_ld_compile): Trim assembler
	warnings about "ignoring incorrect section type".
	(run_ld_link_exec_tests, run_cc_link_tests): Delete old comment.