(#8575) Add loadyaml() function

This change adds a loadyaml() puppet function that takes a path to a
YAML data file and returns the contents as a Puppet variable.  There is
currently no validation of the contents of the file.

This commit is intentionally lacking unit tests because of time
constraints.

Reviewed-by: Dan Bode

lib/puppet/parser/functions/loadyaml.rb

@@ -0,0 +1,20 @@
+module Puppet::Parser::Functions
+
+  newfunction(:loadyaml, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args|
+    Load a YAML file and return the data if it contains an Array, String, or Hash
+    as a Puppet variable.
+
+    For example:
+
+      $myhash = loadyaml('/etc/puppet/data/myhash.yaml')
+    ENDHEREDOC
+
+    unless args.length == 1
+      raise Puppet::ParseError, ("loadyaml(): wrong number of arguments (#{args.length}; must be 1)")
+    end
+
+    YAML.load_file(args[0])
+
+  end
+
+end