find_replace: cover o3 function prologues on every backend

arm64, llvm and the region-interpreter rdrop path now watch the two
prologue words the way the x86-64 jit already did, so icon.replace_function's
lit+jmp patch retires a compiled callee (and clears fn_nat) instead of leaving
a stale stub. three new icon regressions: repeated o3 replace, failed
publication keeps the old entry, and a direct call after warming the region.

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/icon/regression/o3_repeated_replace.zc b/tests/icon/regression/o3_repeated_replace.zc
new file mode 100644
index 0000000..5cad477
--- /dev/null
+++ b/tests/icon/regression/o3_repeated_replace.zc
@@ -0,0 +1,16 @@
+include rt;
+include run;
+include icon;
+// repeated find_replace on an o3 callee must keep the o3 caller's published view
+// current (prologue coverage / generation guard), not a stale compiled stub.
+o3 int target() { return 7; }
+o3 int caller() { int s = 0; for (int i = 0; i < 3; i++) s += target(); return s; }
+fn main() {
+	let seven = run.tokens("7"), eight = run.tokens("8"), nine = run.tokens("9");
+	rt.put_n(caller()); rt.put_c(' ');
+	rt.put_n(icon.find_replace(target, seven, eight)); rt.put_c(' ');
+	rt.put_n(caller()); rt.put_c(' ');
+	rt.put_n(icon.find_replace(target, eight, nine)); rt.put_c(' ');
+	rt.put_n(caller()); rt.put_c(10);
+	return 0;
+}