Win32 Liblist test for system library, fix so finds

Author: mohawk2

lib/ExtUtils/Liblist/Kid.pm

@@ -379,6 +379,7 @@ sub _win32_default_search_paths {
 
     push @libpath, split /;/, $ENV{LIB}          if $VC and $ENV{LIB};
     push @libpath, split /;/, $ENV{LIBRARY_PATH} if $GC and $ENV{LIBRARY_PATH};
+    push @libpath, "$ENV{SYSTEMROOT}\\system32"  if $ENV{SYSTEMROOT};
 
     return @libpath;
 }
@@ -435,8 +436,8 @@ sub _win32_try_attach_extension {
 }
 
 sub _win32_lib_extensions {
-    my @extensions;
-    push @extensions, $Config{'lib_ext'} if $Config{'lib_ext'};
+    my @extensions = grep $_, @Config{qw(lib_ext)};
+    push @extensions, map ".$_", grep $_, @Config{qw(dlext so)};
     push @extensions, '.dll.a' if grep { m!^\.a$! } @extensions;
     push @extensions, '.lib' unless grep { m!^\.lib$! } @extensions;
     return \@extensions;

t/Liblist_Kid.t

@@ -141,6 +141,8 @@ sub test_kid_unix_os2 {
 sub test_kid_win32 {
     my $warnings = "";
     local $SIG{__WARN__} = sub { $warnings .= "@_\n"; };
+    my @got32 = _ext( 'kernel32' );
+    like $got32[0], qr/kernel32/, 'found Win32 system library' or diag 'got: ', explain \@got32;
     is_deeply( [ _ext( 'test' ) ], [ double(quote('test.lib'), '') ], 'existent file results in a path to the file. .lib is default extension with empty %Config' );
     is_deeply( [ _ext( 'c_test' ) ], [ double(quote('lib\CORE\c_test.lib'), '') ], '$Config{installarchlib}/CORE is the default search dir aside from cwd' );
     is_deeply( [ _ext( 'double' ) ], [ double(quote('double.lib'), '') ], 'once an instance of a lib is found, the search stops' );