Remove darwin version in Darwin*NativeConfiguration to avoid confusion

* Since that is the version that CRuby was built on, which might differ
  from the OS version in use in CI.

Author: eregon

src/main/java/org/truffleruby/platform/DarwinAArch64NativeConfiguration.java

@@ -42,7 +42,7 @@
 public final class DarwinAArch64NativeConfiguration extends DefaultNativeConfiguration {
 
     public static void load(NativeConfiguration configuration, RubyContext context) {
-        // Generated from tool/generate-native-config.rb on arm64-darwin20
+        // Generated from tool/generate-native-config.rb on arm64-darwin
         configuration.config("platform.sigaction.sizeof", 16);
         configuration.config("platform.sigaction.sa_handler.offset", 0);
         configuration.config("platform.sigaction.sa_handler.size", 8);

src/main/java/org/truffleruby/platform/DarwinAMD64NativeConfiguration.java

@@ -42,7 +42,7 @@
 public final class DarwinAMD64NativeConfiguration extends DefaultNativeConfiguration {
 
     public static void load(NativeConfiguration configuration, RubyContext context) {
-        // Generated from tool/generate-native-config.rb on x86_64-darwin18
+        // Generated from tool/generate-native-config.rb on x86_64-darwin
         configuration.config("platform.sigaction.sizeof", 16);
         configuration.config("platform.sigaction.sa_handler.offset", 0);
         configuration.config("platform.sigaction.sa_handler.size", 8);

tool/generate-native-config.rb

@@ -85,7 +85,7 @@ def initialize
 
     @file = File.open(java_file, 'wb')
     @file.puts contents[0...from+METHOD_START.length]
-    @file.puts "#{INDENT}// Generated from #{SCRIPT} on #{RUBY_PLATFORM}"
+    @file.puts "#{INDENT}// Generated from #{SCRIPT} on #{RUBY_PLATFORM.sub(/darwin\d+/, 'darwin')}"
     at_exit do
       @file.puts contents[to..-1]
       @file.close