feature_spec.rb: Don't test --enable-all with --zjit*

Author: k0kubun

spec/ruby/command_line/feature_spec.rb

@@ -51,7 +51,7 @@
       env = {'RUBYOPT' => '-w'}
       # Use a single variant here because it can be quite slow as it might enable jit, etc
       ruby_exe(e, options: "--enable-all", env: env).chomp.should == "[\"constant\", \"constant\", true, true]"
-    end
+    end unless defined?(RubyVM::YJIT) && defined?(RubyVM::ZJIT) && RubyVM::ZJIT.enabled? # You're not supposed to enable YJIT with --enable-all when ZJIT options are passed.
   end
 
   it "can be used with all for disable" do