PR sanitizer/81929
	* tree.c (struct replace_placeholders_t): Add pset field.
	(replace_placeholders_r): Call cp_walk_tree with d->pset as
	last argument instead of NULL.  Formatting fix.
	(replace_placeholders): Add pset variable, add its address
	into data.  Pass &pset instead of NULL to cp_walk_tree.

	* g++.dg/ubsan/pr81929.C: New test.

From-SVN: r253106