re PR sanitizer/81929 (exponential slowdown in undefined behavior sanitizer for streaming)
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.