defer support; llgo/ssa: IfThen

cl/_testgo/defer/in.go

@@ -0,0 +1,25 @@
+package main
+
+func f(s string) bool {
+	return len(s) > 5
+}
+
+func fail() {
+	panic("error")
+}
+
+func main() {
+	defer func() {
+		println("hi")
+		if e := recover(); e != nil {
+			println(e.(string))
+		}
+	}()
+	if s := "hello"; f(s) {
+		defer println(s)
+	} else {
+		defer println("world")
+		fail()
+	}
+	defer println("bye")
+}

cl/compile.go

@@ -796,6 +796,8 @@ func (p *context) compileInstr(b llssa.Builder, instr ssa.Instruction) {
 		key := p.compileValue(b, v.Key)
 		val := p.compileValue(b, v.Value)
 		b.MapUpdate(m, key, val)
+	case *ssa.Defer:
+		p.call(b, llssa.Defer, &v.Call)
 	case *ssa.Go:
 		p.call(b, llssa.Go, &v.Call)
 	case *ssa.Panic: