There are many existing tests for WeakMap, WeakSet, WeakRef, and
FinalizationRegistry using Objects as weak values. For symbols-as-weakmap-
keys, we'll want to write tests that parallel these for Symbol keys.
Change the descriptions and filenames of these tests to describe their new
scope of only Object weak values.
Update the front matter of these tests while we're at it, to reflect the
changes to the spec text that the symbols-as-weakmap-keys brings in. (In
some cases, remove irrelevant bits of the front matter.)
See: #2850
Philip Chimento