Add OpenBSD/arm64 support.

Signed-off-by: Kevin Lo <kevlo@kevlo.org>
Change-Id: I6f29bdb55caeec8893f128fdd50bdcc3d058cb3c
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6905
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Pablo Marquez Tello <pablo.tello@arm.com>
Comments-Addressed: Pablo Marquez Tello <pablo.tello@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/SConscript b/SConscript
index 320538e..d8dcaad 100644
--- a/SConscript
+++ b/SConscript
@@ -295,7 +295,7 @@
 version_file = arm_compute_env.Command("src/core/arm_compute_version.embed", "", action=create_version_file)
 arm_compute_env.AlwaysBuild(version_file)
 
-default_cpp_compiler = 'g++' if env['os'] not in ['android', 'macos'] else 'clang++'
+default_cpp_compiler = 'g++' if env['os'] not in ['android', 'macos', 'openbsd'] else 'clang++'
 cpp_compiler = os.environ.get('CXX', default_cpp_compiler)
 
 # Generate embed files
@@ -455,7 +455,8 @@
 arm_compute_env.Append(LINKFLAGS=[undefined_flag])
 arm_compute_env.Append(CPPPATH =[Dir("./src/core/").path] )
 
-arm_compute_env.Append(LIBS = ['dl'])
+if env['os'] != 'openbsd':
+    arm_compute_env.Append(LIBS = ['dl'])
 
 # Load build definitions file
 with (open(Dir('#').path + '/filedefs.json')) as fd: