Follow-up to some recent commits that fixed issues around
jasmine.anything() matching. This simply adds some extra tests that
exercise usage of Symbols with jasmine.anything() and as Map keys.
The previous Map equality code was assuming that the set of keys would
be identical between the two Maps. This change adds insertion-order
tracking for each key with its corresponding key. If one of the two keys
is an asymmetric equality obj, the keys are eq()'d, and if it succeeds,
the corresponding values are compared. Otherwise, the "main" key is
looked up directly in the other object; this is to prevent
similar-looking obj keys with different obj identities from comparing
equal.
Fixes#1432.
