removed TODO

(new rules on type compatibility cover this already)

DELTA=2  (0 added, 2 deleted, 0 changed)
OCL=29094
CL=29096

doc/go_spec.html

@@ -13,8 +13,6 @@ Todo's:
 	a T struct { a b int }.
 [ ] should probably write something about evaluation order of statements even
 	though obvious
-[ ] document new assignment rules (for named types on either side of an
-	assignment, the types must be identical)
 [ ] document T.m mechanism to obtain a function from a method
 -->