[io grant] Fix incorrect information for IO::Path.absolute

The method does not use `$*CWD`, but the object's CWD attribute,
if no base is given.

Author: zoffixznet

doc/Type/IO/Path.pod6

@@ -141,9 +141,13 @@ Returns C<True> if the path is a relative path, and C<False> otherwise.
 
 =head2 method absolute
 
-    method absolute(IO::Path:D: $base = ~$*CWD --> Str)
+    multi method absolute(IO::Path:D: --> Str)
+    multi method absolute(IO::Path:D: $base --> Str)
 
-Returns a new C<Str> object that is an absolute path, based on C<$base>.
+Returns a new C<Str> object that is an absolute path. If the invocant
+is not already an absolute path, it is first made absolute using C<$base>
+as base, if it is provided, or the C<.CWD> attribute the object was
+created with if it is not.
 
 =head2 method relative