Recognize GNU .note.ABI-tag values 5 (syllable) and 6 (nacl)

gdb/
	* defs.h (enum gdb_osabi): Add GDB_OSABI_SYLLABLE and GDB_OSABI_NACL.
	* osabi.c (generic_elf_osabi_sniff_abi_tag_sections): Recognize
	GNU_ABI_TAG_SYLLABLE and GNU_ABI_TAG_NACL.
	* configure.tgt (*-*-nacl*): Set gdb_osabi=GDB_OSABI_NACL.
4 files changed