Merge pull request #1839 from zhouguangyuan0718/main-fix-defer-panic

ssa,test: lower builtin panic in defer paths

Author: xushiwei

cl/_testlibgo/deferpanic/expect.txt

@@ -0,0 +1,2 @@
+run main
+panic in defer

cl/_testlibgo/deferpanic/in.go

@@ -0,0 +1,13 @@
+// LITTEST
+package main
+
+// CHECK: define void @"{{.*}}/deferpanic.main"(){{.*}} {
+func main() {
+	defer func() {
+		e := recover()
+		println(e.(string))
+	}()
+	// CHECK: call void @"{{.*}}/runtime/internal/runtime.Panic"
+	defer panic("panic in defer")
+	println("run main")
+}

ssa/expr.go

@@ -1473,7 +1473,11 @@ func (b Builder) BuiltinCall(fn string, args ...Expr) (ret Expr) {
 			}
 		}
 		panic("invalid argument for unsafe.Offsetof: must be a selector expression")
+	case "panic":
+		b.Panic(args[0])
+		return
 	}
+
 	panic("todo: " + fn)
 }