Please run your test suites

[Earnestly]

I'm using commit 3ede0b96ac2dd99c20027c8f176f0d27e9442619

When running `make check' the follow error is returned:

    cd tests && perl ./run_make_tests.pl -srcdir /tmp/makepkg/make-git/src/make 
-make ../make
    Undefined subroutine &main::catfile called at ./run_make_tests.pl line 176.

A quick look at the file seems to suggest `catfile' is called without
appropriate namespacing, this simple diff corrects it and allows the
test suite to complete without issue:

diff --git a/tests/run_make_tests.pl b/tests/run_make_tests.pl
index e2fddac..a7a5555 100644
--- a/tests/run_make_tests.pl
+++ b/tests/run_make_tests.pl
@@ -173,7 +173,7 @@ sub valid_option
 
    if ($option =~ /^-srcdir$/i) {
        $srcdir = shift @argv;
-       if (! -f catfile($srcdir, 'src', 'gnumake.h')) {
+       if (! -f File::Spec->catfile($srcdir, 'src', 'gnumake.h')) {
            print "$option $srcdir: Not a valid GNU make source directory.\n";
            exit 0;
        }