cpu_arch native fallback

Author: scivision

+stdlib/cpu_arch.m

@@ -2,13 +2,13 @@
 
 function a = cpu_arch()
 
-a = '';
-
 if stdlib.has_dotnet()
   a = System.Runtime.InteropServices.RuntimeInformation.OSArchitecture;
   % https://learn.microsoft.com/en-us/dotnet/core/compatibility/interop/7.0/osarchitecture-emulation
 elseif stdlib.has_java()
   a = javaMethod("getProperty", "java.lang.System", "os.arch");
+else
+  a = computer('arch');
 end
 
 try  %#ok<*TRYNC>

test/TestSys.m

@@ -69,7 +69,7 @@ function test_cpu_arch(tc)
 tc.assumeTrue(stdlib.has_dotnet() || stdlib.has_java())
 
 arch = stdlib.cpu_arch();
-tc.verifyGreaterThan(strlength(arch), 0)
+tc.verifyGreaterThan(strlength(arch), 0, "CPU architecture should not be empty")
 end
 
 function test_ram_total(tc)