Convert objects with #to_path in $LOAD_PATH

* Fixes #2119

Author: eregon

CHANGELOG.md

@@ -44,6 +44,7 @@ Compatibility:
 * Support refinements for `#to_s` called by string interpolation (#2110, @ssnickolay)
 * Module#using raises error in method scope (#2112, @ssnickolay)
 * `File#path` now returns a new mutable String on every call like MRI (#2115).
+* Convert objects with `#to_path` in `$LOAD_PATH` (#2119).
 
 Performance:
 

src/main/ruby/truffleruby/core/truffle/feature_loader.rb

@@ -279,7 +279,7 @@ def self.features_index_add(feature, offset)
 
     def self.get_expanded_load_path
       unless Primitive.array_storage_equal?(@load_path_copy, $LOAD_PATH)
-        @expanded_load_path = $LOAD_PATH.map { |path| Primitive.canonicalize_path(path) }
+        @expanded_load_path = $LOAD_PATH.map { |path| Primitive.canonicalize_path(Truffle::Type.coerce_to_path(path)) }
         @loaded_features_copy = $LOAD_PATH.dup
       end
       @expanded_load_path