HLS: Ignore empty NALU to avoid error. v6.0.65 (#3750)

For the DJI M30, there is a bug where empty NALU packets with a size of
zero are causing issues with HLS streaming. This bug leads to random
unpublish events due to the SRS disconnecting the connection for the HLS
module when it fails to handle empty NALU packets.

To address this bug, we have patched the system to ignore any empty NALU
packets with a size of zero. Additionally, we have created a tool in the
srs-bench to replay pcapng files captured by tcpdump or Wireshark. We
have also added utest using mprotect and asan to detect any memory
corruption.

It is important to note that this bug has been fixed in versions 4.0.271
6477f31004 and 5.0.170
939f6b484b. This patch specifically
addresses the issue in SRS 6.0.

Please be aware that there is another commit related to this bug that
partially fixes the issue but still leaves a small problem for asan to
detect memory corruption. This commit,
577cd299e1, only ignores empty NALU
packets but still reads beyond the memory.

---------

Co-authored-by: chundonglinlin <chundonglinlin@163.com>

trunk/3rdparty/srs-bench/vendor/golang.org/x/net/internal/socket/zsys_openbsd_ppc64.go

@@ -4,27 +4,27 @@
 package socket
 
 type iovec struct {
-	Base *byte
-	Len  uint64
+	Base	*byte
+	Len	uint64
 }
 
 type msghdr struct {
-	Name       *byte
-	Namelen    uint32
-	Iov        *iovec
-	Iovlen     uint32
-	Control    *byte
-	Controllen uint32
-	Flags      int32
+	Name		*byte
+	Namelen		uint32
+	Iov		*iovec
+	Iovlen		uint32
+	Control		*byte
+	Controllen	uint32
+	Flags		int32
 }
 
 type cmsghdr struct {
-	Len   uint32
-	Level int32
-	Type  int32
+	Len	uint32
+	Level	int32
+	Type	int32
 }
 
 const (
-	sizeofIovec  = 0x10
-	sizeofMsghdr = 0x30
+	sizeofIovec	= 0x10
+	sizeofMsghdr	= 0x30
 )

trunk/3rdparty/srs-bench/vendor/golang.org/x/net/internal/socket/zsys_openbsd_riscv64.go

@@ -4,27 +4,27 @@
 package socket
 
 type iovec struct {
-	Base *byte
-	Len  uint64
+	Base	*byte
+	Len	uint64
 }
 
 type msghdr struct {
-	Name       *byte
-	Namelen    uint32
-	Iov        *iovec
-	Iovlen     uint32
-	Control    *byte
-	Controllen uint32
-	Flags      int32
+	Name		*byte
+	Namelen		uint32
+	Iov		*iovec
+	Iovlen		uint32
+	Control		*byte
+	Controllen	uint32
+	Flags		int32
 }
 
 type cmsghdr struct {
-	Len   uint32
-	Level int32
-	Type  int32
+	Len	uint32
+	Level	int32
+	Type	int32
 }
 
 const (
-	sizeofIovec  = 0x10
-	sizeofMsghdr = 0x30
+	sizeofIovec	= 0x10
+	sizeofMsghdr	= 0x30
 )