Allow lists to contain void elements if not optimizing and not lazy

LSO allows this. The compiler does too, but it chokes in RAIL.

This affected a test, which has been adjusted too.

Untyped lazy list elements can no longer be used in isolation in expression lists (including FOR initializator and iterator).

Also rename the terribly named 'self.forbidlabels' to 'self.optenabled' which is more descriptive.

testparser.py

@@ -128,7 +128,7 @@ class Test02_Parser(UnitTestCase):
         self.assertRaises(EParseFunctionMismatch, self.parser.parse, '''f(integer i){f(f(1));}''')
         self.assertRaises(EParseFunctionMismatch, self.parser.parse, '''f(integer i){f();}''')
         self.assertRaises(EParseDeclarationScope, self.parser.parse, '''f(){if (1) integer i;}''')
-        self.assertRaises(EParseTypeMismatch, self.parser.parse, '''f(){[f()];}''')
+        self.assertRaises(EParseTypeMismatch, self.parser.parse, '''f(){[f()];}''', ('optimize',))
         self.assertRaises(EParseTypeMismatch, self.parser.parse, '''f(){3.||2;}''')
         self.assertRaises(EParseTypeMismatch, self.parser.parse, '''f(){3||2.;}''')
         self.assertRaises(EParseTypeMismatch, self.parser.parse, '''f(){3.|2;}''')
@@ -185,6 +185,9 @@ class Test02_Parser(UnitTestCase):
 
         self.assertRaises(EParseUndefined, self.parser.parse, '''key a=b;key b;default{timer(){}}''',
             ['extendedglobalexpr'])
+
+        self.parser.parse('''f(){[f()];}default{timer(){}}''')
+
         # Force a list constant down its throat, to test coverage of LIST_VALUE
         self.parser.constants['LISTCONST']=[1,2,3]
         print self.outscript.output(self.parser.parse('default{timer(){LISTCONST;}}'))