Fixed codepage for utime [Bug #17626]

Should use the given codepage argument.

Co-Authored-By: Nobuyoshi Nakada <nobu@ruby-lang.org>

test/ruby/test_file_exhaustive.rb

@@ -679,6 +679,13 @@ class TestFileExhaustive < Test::Unit::TestCase
     File.utime(t + 1, t + 2, zerofile)
     assert_equal(t + 1, File.atime(zerofile))
     assert_equal(t + 2, File.mtime(zerofile))
+    Dir.mktmpdir do |dir|
+      Dir.chdir do
+        path = "foo\u{30b3 30d4 30fc}"
+        File.write(path, "") rescue next
+        assert_equal(1, File.utime(nil, nil, path))
+      end
+    end
   end
 
   def test_utime_symlinkfile

win32/win32.c

@@ -7400,7 +7400,7 @@ wutimensat(int dirfd, const WCHAR *path, const struct timespec *times, int flags
 static int
 w32_utimensat(int dirfd, const char *path, const struct timespec *times, int flags, UINT cp)
 {
-    WCHAR *wpath = mbstr_to_wstr(filecp(), path, -1, NULL);
+    WCHAR *wpath = mbstr_to_wstr(cp, path, -1, NULL);
     int ret = -1;
 
     if (wpath) {