freebsd11_network: Add mtx_trylock() and curcpu.

These are needed for the "non-legacy" TX path in ipro1000.
Also remove the "spinlock" member from struct mtx; struct mtx_spin
is different (and not implemented by us presently.)

src/libs/compat/freebsd11_network/Jamfile

@@ -41,6 +41,7 @@ KernelStaticLibrary libfreebsd11_network.a :
 	mbuf.c
 	mii.c
 	mutex.c
+	pcpu.cpp
 	priv.cpp
 	smp.c
 	subr_autoconf.cpp

src/libs/compat/freebsd11_network/compat/sys/_mutex.h

@@ -17,7 +17,6 @@ struct mtx {
 			mutex			lock;
 			thread_id		owner;
 		}					mutex;
-		int32				spinlock;
 		recursive_lock		recursive;
 	} u;
 };

src/libs/compat/freebsd11_network/compat/sys/mutex.h

@@ -54,6 +54,22 @@ mtx_lock(struct mtx* mutex)
 }
 
 
+static inline int
+mtx_trylock(struct mtx* mutex)
+{
+	if (mutex->type == MTX_DEF) {
+		if (mutex_trylock(&mutex->u.mutex.lock) != B_OK)
+			return 0;
+		mutex->u.mutex.owner = find_thread(NULL);
+		return 1;
+	} else if (mutex->type == MTX_RECURSE) {
+		if (recursive_lock_trylock(&mutex->u.recursive) != B_OK)
+			return 0;
+		return 1;
+	}
+}
+
+
 static inline void
 mtx_unlock(struct mtx* mutex)
 {

src/libs/compat/freebsd11_network/compat/sys/pcpu.h

@@ -10,7 +10,9 @@
 
 
 struct thread;
+int get_curcpu();
 
+#define curcpu (get_curcpu())
 #define curthread ((struct thread*)NULL)
 	/* NOTE: Dereferencing curthread will crash, which is intentional. There is
 	   no FreeBSD compatible struct thread and Haiku's should not be used as it

src/libs/compat/freebsd11_network/pcpu.cpp

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2018, Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+
+#include <OS.h>
+#include <smp.h>
+
+extern "C" {
+#include <compat/sys/pcpu.h>
+};
+
+
+int32_t
+get_curcpu()
+{
+	return smp_get_current_cpu();
+}