convert elf_link_hash macros to inline functions

Involves a bit of editing as we now need to be more precise in pointer
types.

bfd/
	* elf-bfd.h (is_elf_hash_table): Convert macro to inline function.
	(elf_link_hash_lookup, elf_link_hash_traverse): Likewise.
	(elf_hash_table, elf_hash_table_id): Likewise.
	* elf32-arm.c (elf32_arm_setup_section_lists): Delete redundant
	is_elf_hash_table check.
	* elf32-csky.c (elf32_csky_setup_section_lists): Likewise.
	* elf32-hppa.c (clobber_millicode_symbols): Correct param types.
	* elf64-alpha.c (elf64_alpha_output_extsym): Likewise.
	* elfnn-ia64.c (elfNN_ia64_global_dyn_info_free: Likewise.
	(elfNN_ia64_global_dyn_sym_thunk: Likewise.
	* elf64-ia64-vms.c (elf64_ia64_global_dyn_info_free): Likewise.
	(elf64_ia64_global_dyn_sym_thunk): Likewise.
	(elf64_vms_link_add_object_symbols): Pass base type of hash table
	to is_elf_hash_table.
	* elflink.c (_bfd_elf_dynamic_symbol_p): Likewise.
	(_bfd_elf_symbol_refs_local_p, _bfd_elf_add_dynamic_entry): Likewise.
	(_bfd_elf_strip_zero_sized_dynamic_sections): Likewise.
	(_bfd_elf_link_check_relocs, elf_link_add_object_symbols): Likewise.
	(bfd_elf_final_link): Likewise.
	* elfnn-aarch64.c (elfNN_aarch64_setup_section_lists): Likewise.
	* elf64-ppc.c (ppc64_elf_set_toc): Likewise.  Use bfd_link_hash_lookup.
ld/
	* emultempl/mipself.em (mips_create_output_section_statements):
	Pass base type of hash table to is_elf_hash_table.
	* ldelf.c (ldelf_after_open): Likewise.

ld/ldelf.c

@@ -1001,7 +1001,7 @@ ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd,
   after_open_default ();
 
   htab = elf_hash_table (&link_info);
-  if (!is_elf_hash_table (htab))
+  if (!is_elf_hash_table (&htab->root))
     return;
 
   if (command_line.out_implib_filename)