[ruby/rubygems] Fix incompatible function pointer type error with Xcode 26.5 beta

Xcode 26.5 beta ships a clang that promotes -Wincompatible-function-pointer-types to an error by default. The test's inline C extension defined `VALUE foo()` (taking no arguments) but passed it to `rb_define_global_function` which expects `VALUE (*)(VALUE)` through Ruby's RBIMPL_ANYARGS dispatch macro. Adding the `VALUE self` parameter fixes the signature mismatch.

ruby/rubygems@393490d8a5

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

spec/bundler/install/gemfile/git_spec.rb

@@ -1404,7 +1404,7 @@
         File.open(git_reader.path.join("ext/foo.c"), "w") do |file|
           file.write <<-C
             #include "ruby.h"
-            VALUE foo() { return INT2FIX(#{i}); }
+            VALUE foo(VALUE self) { return INT2FIX(#{i}); }
             void Init_foo() { rb_define_global_function("foo", &foo, 0); }
           C
         end