Fix placement of forced local symbols in the dynamic symbol table.

Fix placement of forced local symbols in the dynamic symbol table.

Gold was not placing forced-local symbols (e.g., hidden visibility)
at the front of the dynamic symbol table, or including them in the
count of local symbols recorded in the .dynsym section's sh_info field.

gold/
	* layout.cc (Layout::finalize): Track count of forced-local symbols
	in .dynsym.
	(Layout::create_symtab_sections): Add local_dynamic_count parameter;
	use that instead of sh_info value.
	(Layout::create_dynamic_symtab): Add pforced_local_dynamic_count
	parameter; pass it to Symtab::set_dynsym_indexes().  Include forced
	locals in sh_info value.  Pass index of first real global to
	Dynobj::create_gnu_hash_table() and Dynobj::create_elf_hash_table().
	* layout.h (Layout::create_symtab_sections): Add local_dynamic_count
	parameter.
	(Layout::create_dynamic_symtab): Add pforced_local_dynamic_count
	parameter.
	* symtab.cc (Symbol_table::set_dynsym_indexes): Add pforced_local_count
	parameter.  Process forced-local symbols first and return the count.
	(Symbol_table::finalize): Update comments.
	* symtab.h (Symbol_table::set_dynsym_indexes): Add pforced_local_count
	parameter.
	(Symbol_table::first_dynamic_global_index_): Update comment.
	(Symbol_table::dynamic_count_): Update comment.
	* testsuite/Makefile.am (ifuncmod1.sh): New test case.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/ifuncmod1.sh: New shell script.