fix os.read_dir with symlinks

tests/core/normal.odin

@@ -30,6 +30,7 @@ download_assets :: proc() {
 @(require) import "mem"
 @(require) import "net"
 @(require) import "odin"
+@(require) import "os"
 @(require) import "path/filepath"
 @(require) import "reflect"
 @(require) import "runtime"

tests/core/os/dir/alink.txt

@@ -0,0 +1 @@
+./a.txt

tests/core/os/os.odin

@@ -0,0 +1,35 @@
+package tests_core_os
+
+import "core:os"
+import "core:slice"
+
+import "core:testing"
+
+@(test)
+read_dir :: proc(t: ^testing.T) {
+	fd, errno := os.open(#directory + "/dir")
+	testing.expect_value(t, errno, os.ERROR_NONE)
+	defer os.close(fd)
+
+	dir, errno2 := os.read_dir(fd, -1)
+	testing.expect_value(t, errno2, os.ERROR_NONE)
+	defer os.file_info_slice_delete(dir)
+
+	slice.sort_by_key(dir, proc(fi: os.File_Info) -> string { return fi.name })
+
+	testing.expect_value(t, len(dir), 3)
+
+	testing.expect_value(t, dir[0].name, "alink.txt")
+	testing.expect(t, !dir[0].is_dir, "is a directory")
+	when ODIN_OS == .Windows {
+		testing.expect(t, dir[0].mode & os.File_Mode_Sym_Link != 0, "not a symlink")
+	} else {
+		testing.expect(t, os.S_ISLNK(auto_cast dir[0].mode), "not a symlink")
+	}
+
+	testing.expect_value(t, dir[1].name, "b.txt")
+
+	testing.expect_value(t, dir[2].name, "sub")
+	testing.expect(t, dir[2].is_dir, "is not a directory")
+}
+