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, 19 insertions, 0 deletions

diff --git a/tests/icon/regression/o3_failed_keeps_old.zc b/tests/icon/regression/o3_failed_keeps_old.zc
new file mode 100644
index 0000000..f750a84
--- /dev/null
+++ b/tests/icon/regression/o3_failed_keeps_old.zc
@@ -0,0 +1,19 @@
+include rt;
+include run;
+include icon;
+typecheck on;
+// a rejected publication must leave the previous entry (and any o3 caller of it)
+// unchanged: status 6, still returning the last successfully published body.
+o3 int target() { return 4; }
+o3 int caller() { return target() + target(); }
+fn main() {
+	let four = run.tokens("4"), five = run.tokens("5");
+	rt.put_n(caller()); rt.put_c(' ');
+	rt.put_n(icon.find_replace(target, four, five)); rt.put_c(' ');
+	rt.put_n(caller()); rt.put_c(' ');
+	let bad_pat = run.tokens("return $int;"), bad_rep = run.tokens("return \"x\";");
+	rt.put_n(icon.find_replace(target, bad_pat, bad_rep)); rt.put_c(' ');
+	rt.put_n(icon.error()); rt.put_c(' ');
+	rt.put_n(caller()); rt.put_c(10);
+	return 0;
+}