Support VERIFY_RETURN_TYPE elision with unused operand

This handles the degenerate case where SCCP replaced the value in
the RETURN opcode with a constant, but the VERIFY_RETURN is still
there. We can still apply the same optimization, just don't need
to adjust the use list in this case.

The result is still sub-optimal in that a dead QM_ASSIGN is left
behind.

1 files changed, 23 insertions, 0 deletions

diff --git a/ext/opcache/tests/opt/verify_return_type.phpt b/ext/opcache/tests/opt/verify_return_type.phpt
index 3838cd8b0c..7f52c829a4 100644
--- a/ext/opcache/tests/opt/verify_return_type.phpt
+++ b/ext/opcache/tests/opt/verify_return_type.phpt
@@ -37,6 +37,16 @@ class Test2 {
     }
 }
 
+class Test3 {
+    private function getBool() {
+        return true;
+    }
+
+    private function getBool2(): bool {
+        return $this->getBool();
+    }
+}
+
 ?>
 --EXPECTF--
 $_main:
@@ -91,3 +101,16 @@ Test2::getInt3:
 0003 V1 = DO_FCALL
 0004 VERIFY_RETURN_TYPE V1
 0005 RETURN V1
+
+Test3::getBool:
+     ; (lines=1, args=0, vars=0, tmps=0)
+     ; (after optimizer)
+     ; %s
+0000 RETURN bool(true)
+
+Test3::getBool2:
+     ; (lines=2, args=0, vars=0, tmps=1)
+     ; (after optimizer)
+     ; %s
+0000 V0 = QM_ASSIGN bool(true)
+0001 RETURN bool(true)