* cpppch.c (reset_ht): Remove.
	(cpp_read_state): Remove loop to reset hashtable identifiers.
	* ggc-common.c (gt_pch_save): Add call to gt_pch_fixup_stringpool
	after pch file is written.
	* ggc.h (gt_pch_fixup_stringpool): Declare.
	* stringpool.c (ht_copy_and_clear): Define.  Callback.  Copy
	hashnode's value to another hashtable, then clear the original.
	(saved_ident_hash): Define.
	(gt_pch_save_stringpool): Create saved_ident_hash, use it to
	store definitions in ident_hash, and clear ident_hash.
	(gt_pch_fixup_stringpool): Define.  Restore definitions from
	saved_ident_hash to ident_hash, then destroy saved_ident_hash.

From-SVN: r65215