Fix SysV-style hash table when --hash-style=both.

Fix SysV-style hash table when --hash-style=both.

When --hash-style-both is used, gold currently builds the sysv hash
table first, then the gnu hash table. Building the gnu hash table
renumbers the dynamic symbol table, invalidating the sysv hash
table. This patch reverses the order in which the hash tables are
build so that both hash tables are correct.

gold/
	PR gold/13597
	* layout.cc (Layout::create_dynamic_symtab): Build gnu-style
	hash table before sysv-style hash table.