base: do not allow unnamed threads

fix #901

os/src/server/iso9660/main.cc

@@ -217,6 +217,8 @@ namespace Iso {
 
 		public:
 
+			Pager() : Thread("iso_pager") { }
+
 			Signal_receiver *signal_receiver() { return &_receiver; }
 
 			void entry()

os/src/server/mixer/mixer.cc

@@ -116,7 +116,7 @@ class Audio_out::Mixer : public Thread<1024 * sizeof(addr_t)>
 
 		Mixer()
 		:
-			Thread("mixer"),
+			Thread("audio_out_mixer"),
 			_sleep_lock(Lock::LOCKED), _left("left", false, true),
 			_right("right", false, true)
 		{

os/src/server/nic_loopback/main.cc

@@ -128,6 +128,7 @@ namespace Nic {
 			:
 				Genode::Allocator_avl(rx_block_md_alloc),
 				Tx_rx_communication_buffers(tx_buf_size, rx_buf_size),
+				Thread("nic_packet_handler"),
 				Session_rpc_object(Tx_rx_communication_buffers::tx_ds(),
 				                   Tx_rx_communication_buffers::rx_ds(),
 				                   static_cast<Genode::Range_allocator *>(this), ep)

os/src/server/part_blk/main.cc

@@ -59,7 +59,7 @@ namespace Block {
 				public:
 
 					Tx_thread(Session_component *session)
-					: _session(session) { }
+					: Thread("block_session_tx"), _session(session) { }
 
 					void entry()
 					{

os/src/server/rom_loopdev/main.cc

@@ -51,7 +51,8 @@ namespace Block {
 					          addr_t             dev_addr,
 					          size_t             dev_size,
 					          size_t             blk_size)
-					: _session(session),
+					: Thread("block_session_tx"),
+					  _session(session),
 					  _dev_addr(dev_addr),
 					  _dev_size(dev_size),
 					  _blk_size(blk_size) { }

os/src/server/vmm/main.cc

@@ -331,7 +331,8 @@ namespace Genode {
 			Vmm(addr_t tsc_base, addr_t tpc_base,
 				addr_t sys_base, addr_t sp810_base,
 				Vm    *vm)
-			: _tsc_io_mem(tsc_base,     0x1000),
+			: Thread("vmm_signal_handler"),
+			  _tsc_io_mem(tsc_base,     0x1000),
 			  _tpc_io_mem(tpc_base,     0x1000),
 			  _sys_io_mem(sys_base,     0x1000),
 			  _sp810_io_mem(sp810_base, 0x1000),