Add type restrictions to Dir (#15697)

Author: Vici37

src/dir.cr

@@ -284,14 +284,14 @@ class Dir
   # Dir.mkdir("testdir")
   # Dir.exists?("testdir") # => true
   # ```
-  def self.mkdir(path : Path | String, mode = 0o777) : Nil
+  def self.mkdir(path : Path | String, mode : Int32 = 0o777) : Nil
     Crystal::System::Dir.create(path.to_s, mode)
   end
 
   # Creates a new directory at the given path, including any non-existing
   # intermediate directories. The linux-style permission mode can be specified,
   # with a default of 777 (0o777).
-  def self.mkdir_p(path : Path | String, mode = 0o777) : Nil
+  def self.mkdir_p(path : Path | String, mode : Int32 = 0o777) : Nil
     return if Dir.exists?(path)
 
     path = Path.new path

src/dir/glob.cr

@@ -64,7 +64,7 @@ class Dir
   # equivalent to
   # `match: File::MatchOptions.glob_default | File::MatchOptions::DotFiles`.
   @[Deprecated("Use the overload with a `match` parameter instead")]
-  def self.glob(*patterns : Path | String, match_hidden, follow_symlinks = false) : Array(String)
+  def self.glob(*patterns : Path | String, match_hidden : Bool, follow_symlinks : Bool = false) : Array(String)
     glob(patterns, match: match_hidden_to_options(match_hidden), follow_symlinks: follow_symlinks)
   end