PR target/58115
	* tree-core.h (struct target_globals): New forward declaration.
	(struct tree_target_option): Add globals field.
	* tree.h (TREE_TARGET_GLOBALS): Define.
	(prepare_target_option_nodes_for_pch): New prototype.
	* target-globals.h (struct target_globals): Define even if
	!SWITCHABLE_TARGET.
	* tree.c (prepare_target_option_node_for_pch,
	prepare_target_option_nodes_for_pch): New functions.
	* config/i386/i386.h (SWITCHABLE_TARGET): Define.
	* config/i386/i386.c: Include target-globals.h.
	(ix86_set_current_function): Instead of doing target_reinit
	unconditionally, use save_target_globals_default_opts and
	restore_target_globals.
c-family/
	* c-pch.c (c_common_write_pch): Call
	prepare_target_option_nodes_for_pch.

From-SVN: r206478