cmd/compile: don't inline functions that call recover

recover determines whether it's being called by a deferred frame by
matching its caller's argument frame pointer with the one recorded in
the panic object. That means its caller needs a valid and unique
argument frame pointer, so it must not be inlined.

With this fix, test/recover.go passes with -l=4.

Fixes #23557.

Change-Id: I1f32a624c49e387cfc67893a0829bb248d69c3d4
Reviewed-on: https://go-review.googlesource.com/90035
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/compile/internal/gc/inl.go

@@ -314,12 +314,18 @@ func (v *hairyVisitor) visit(n *Node) bool {
 		}
 
 	// Things that are too hairy, irrespective of the budget
-	case OCALL, OCALLINTER, OPANIC, ORECOVER:
+	case OCALL, OCALLINTER, OPANIC:
 		if Debug['l'] < 4 {
 			v.reason = "non-leaf op " + n.Op.String()
 			return true
 		}
 
+	case ORECOVER:
+		// recover matches the argument frame pointer to find
+		// the right panic value, so it needs an argument frame.
+		v.reason = "call to recover"
+		return true
+
 	case OCLOSURE,
 		OCALLPART,
 		ORANGE,