Add BSD support to the JNISystemDependency

Supports all BSDs that Meson currently supports.

Fixes #10883

docs/markdown/snippets/jni_system_dependency_bsd_support.md

@@ -0,0 +1,4 @@
+## BSD support for the `jni` dependency
+
+This system dependency now supports all BSD systems that Meson currently
+supports, including FreeBSD, NetBSD, OpenBSD, and DragonflyBSD.

mesonbuild/dependencies/dev.py

@@ -618,6 +618,14 @@ class JNISystemDependency(SystemDependency):
             return 'darwin'
         elif m.is_sunos():
             return 'solaris'
+        elif m.is_freebsd():
+            return 'freebsd'
+        elif m.is_netbsd():
+            return 'netbsd'
+        elif m.is_openbsd():
+            return 'openbsd'
+        elif m.is_dragonflybsd():
+            return 'dragonfly'
 
         return None