lang: funcs: core: Add value functions

This adds a new series of "get*" functions which can read values from
the associated "value" resources. The key name of the function must
match the name value of the resource for things to work.

Type unification isn't yet perfect in these scenarios, so you should use
casually and with caution.

examples/lang/value-resource-get.mcl

@@ -0,0 +1,30 @@
+import "value"
+
+value "hello1" {
+	#any => 42,	# can be any type
+	any => "wow",	# can be any type
+}
+value "hello2" {
+	any => "whatever",	# TODO: remove the temporary placeholder here
+	#any => "",	# XXX: remove any placeholder to see the bug when absent
+}
+
+test "test" {
+	#anotherstr => "", # get it from send/recv
+}
+
+Value["hello1"].any -> Value["hello2"].any
+Value["hello2"].any -> Test["test"].anotherstr
+
+$ret1 = value.get_str("hello1")	# name of value resource
+$ret2 = value.get_str("hello2")	# name of value resource
+
+test "get1" {
+	anotherstr => $ret1->value,
+	onlyshow => ["AnotherStr",], # displays nicer
+}
+
+test "get2" {
+	anotherstr => $ret2->value,
+	onlyshow => ["AnotherStr",],
+}

examples/lang/value-resource-simple.mcl

@@ -0,0 +1,19 @@
+value "hello" {
+	any => "whatever",
+}
+
+test "test" {
+	#anotherstr => "", # get it from send/recv
+	onlyshow => ["AnotherStr",], # displays nicer
+}
+
+Value["hello"].any -> Test["test"].anotherstr
+
+import "value"
+
+$ret = value.get_str("hello")	# name of value resource
+
+test "get" {
+	anotherstr => $ret->value,
+	onlyshow => ["AnotherStr",], # displays nicer
+}