Add Solaris specific ELF note processing

Add Solaris specific ELF note processing

Add elfcore_grok_solaris_note function that enables to
obtain process status, register values, and program info
from Solaris's core files.

bfd/
	* elf.c (elfcore_grok_solaris_note): Solaris specific ELF
	note parser. Better GDB's coredump analysis on Solaris...
	(elfcore_grok_solaris_note_impl): New function.
	(elfcore_grok_solaris_prstatus): New function.
	(elfcore_grok_solaris_info): New function.
	(elfcore_grok_solaris_lwpstatus): New function.
	(elf_parse_notes): Added "CORE" groker element.
include/
	* elf/common.h: Add note segment constants for core files on
	Solaris systems.