-------- simple upvalues tests --------
6
5
f1()=	6
g1()=	5
6
5
f2()=	6
g2()=	5
g1()=	4
f1()=	5
simplevalues result:	true
----------- upvalued in middle ------------
x=	3
y=	5
z=	7
x=	x
y=	y
z=	z
true
--------- nested upvalues ----------
10	20
nestedupvaluestest result:	true