runtime: Record jmpdefer's argument size.

Fixes bug 6055.

R=golang-dev, bradfitz, dvyukov, khr
CC=golang-dev
https://golang.org/cl/12536045

src/pkg/runtime/asm_386.s

@@ -537,7 +537,7 @@ TEXT runtime·atomicstore64(SB), NOSPLIT, $0-12
 // 1. pop the caller
 // 2. sub 5 bytes from the callers return
 // 3. jmp to the argument
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0
+TEXT runtime·jmpdefer(SB), NOSPLIT, $0-8
 	MOVL	4(SP), DX	// fn
 	MOVL	8(SP), BX	// caller sp
 	LEAL	-4(BX), SP	// caller sp after CALL

src/pkg/runtime/asm_amd64.s

@@ -577,7 +577,7 @@ TEXT runtime·atomicstore64(SB), NOSPLIT, $0-16
 // 1. pop the caller
 // 2. sub 5 bytes from the callers return
 // 3. jmp to the argument
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0
+TEXT runtime·jmpdefer(SB), NOSPLIT, $0-16
 	MOVQ	8(SP), DX	// fn
 	MOVQ	16(SP), BX	// caller sp
 	LEAQ	-8(BX), SP	// caller sp after CALL

src/pkg/runtime/asm_arm.s

@@ -367,7 +367,7 @@ TEXT runtime·lessstack(SB), NOSPLIT, $-4-0
 // 1. grab stored LR for caller
 // 2. sub 4 bytes to get back to BL deferreturn
 // 3. B to fn
-TEXT runtime·jmpdefer(SB), NOSPLIT, $0
+TEXT runtime·jmpdefer(SB), NOSPLIT, $0-8
 	MOVW	0(SP), LR
 	MOVW	$-4(LR), LR	// BL deferreturn
 	MOVW	fn+0(FP), R7

test/fixedbugs/issue6055.go

+// run
+
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type Closer interface {
+	Close()
+}
+
+func nilInterfaceDeferCall() {
+	var x Closer
+	defer x.Close()
+}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("did not panic")
+		}
+	}()
+	f()
+}
+
+func main() {
+	shouldPanic(nilInterfaceDeferCall)
+}