Make t/harness collect items on Win32

Hello,

226de479579f4a84dd17654b44e5aef323b0a403 broke bleadperl testing on 
Win32, because the following code rejects Windows paths:

	for (@last) {
	    m!(.*/)! or die "'$_'";
	    push @{$dir{$1}}, $_;
	    $total_time{$1} += $times{$_} || 0;
	}

The symptom is the following:

   X:\...>dmake test
   ...
   cd ..\t && ..\perl.exe -I..\lib harness
   No saved state, selection will be empty
   '..\ext\Attribute-Handlers\t\constants.t' at harness line 215.
   dmake:  Error code 255, while making 'test'

   X:\...>

The attached patch canonicalizes the directory separator, just like it 
is done a few lines below this change, converting "\\" to "/". It tests 
OK against a recent (within the last 24h) bleadperl.

-max

• Make t/harness collect items on Win32 by Max Maischein
• RE: Make t/harness collect items on Win32 by Steve Hay
• Re: Make t/harness collect items on Win32 by Max Maischein