merge revision(s) 1b89b99941548fdb65305dd9a412082e7fdba45a: [Backport #17534]

	Mark pattern labels as unremoveable

	Peephole optimization doesn't play well with find pattern at
	least. The only case when a pattern matching could have
	unreachable patterns is when we have lasgn/dasgn node, which
	shouldn't happen in real-life.

	Fixes https://bugs.ruby-lang.org/issues/17534
	---
	 compile.c                          |  2 +-
	 test/ruby/test_pattern_matching.rb | 10 ++++++++++
	 2 files changed, 11 insertions(+), 1 deletion(-)

1 files changed, 1 insertions, 1 deletions

diff --git a/compile.c b/compile.c
index c62deafd23..a5e082f46d 100644
--- a/compile.c
+++ b/compile.c
@@ -6400,11 +6400,11 @@ compile_case3(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const orig_no
             int pat_line = nd_line(pattern);
             LABEL *next_pat = NEW_LABEL(pat_line);
             ADD_INSN (cond_seq, pat_line, dup);
-
             // NOTE: set deconstructed_pos to the current cached value location
             // (it's "under" the matchee value, so it's position is 2)
             CHECK(iseq_compile_pattern_each(iseq, cond_seq, pattern, l1, next_pat, FALSE, 2));
             ADD_LABEL(cond_seq, next_pat);
+            LABEL_UNREMOVABLE(next_pat);
         }
         else {
             COMPILE_ERROR(ERROR_ARGS "unexpected node");