(PUP-2755) Remove special handling of iterative functions / cleanup

This fixes comments from review. It also removes the special
handling of the iterative functions (special case to avoid
having their arguments transformed) as this is no longer needed.

lib/puppet/pops/evaluator/runtime3_support.rb

@@ -223,20 +223,17 @@ def coerce_numeric(v, o, scope)
     n
   end
 
-  # Horrible cheat while waiting for iterative functions to be 4x
-  FUNCTIONS_4x = { 'map' => true, 'each'=>true, 'filter' => true, 'reduce' => true, 'slice' => true }
   def call_function(name, args, o, scope)
-    # Call via 4x API if it is available, and the function exists
-    #
-    if loaders = scope.compiler.loaders
-      # find the loader that loaded the code, or use the private_environment_loader (sees env + all modules)
-      adapter = Puppet::Pops::Utils.find_adapter(o, Puppet::Pops::Adapters::LoaderAdapter)
-      loader = adapter.nil? ? loaders.private_environment_loader : adapter.loader
-      if loader && func = loader.load(:function, name)
-        return func.call(scope, *args)
-      end
+    # Call via 4x API if the function exists there
+    loaders = scope.compiler.loaders
+    # find the loader that loaded the code, or use the private_environment_loader (sees env + all modules)
+    adapter = Puppet::Pops::Utils.find_adapter(o, Puppet::Pops::Adapters::LoaderAdapter)
+    loader = adapter.nil? ? loaders.private_environment_loader : adapter.loader
+    if loader && func = loader.load(:function, name)
+      return func.call(scope, *args)
     end
 
+    # Call via 3x API if function exists there
     fail(Puppet::Pops::Issues::UNKNOWN_FUNCTION, o, {:name => name}) unless Puppet::Parser::Functions.function(name)
 
     # TODO: if Puppet[:biff] == true, then 3x functions should be called via loaders above
@@ -248,7 +245,7 @@ def call_function(name, args, o, scope)
     # directly, when this has been done, this special filtering out can be removed
 
     # NOTE: Passing an empty string last converts :undef to empty string
-    mapped_args = FUNCTIONS_4x[name] ? args : args.map {|a| convert(a, scope, '') }
+    mapped_args = args.map {|a| convert(a, scope, '') }
     result = scope.send("function_#{name}", mapped_args)
     # Prevent non r-value functions from leaking their result (they are not written to care about this)
     Puppet::Parser::Functions.rvalue?(name) ? result : nil