Fix type updating for indirect call effects

[stevenfontanella]

Part of #8615. Fixes #8833 which was wrong. The earlier fix never touched newTypeEffects at all. It passed tests and fixed the breakage only incidentally by being maximally conservative and losing all indirect call effects in the case of a type update. Fix this logic and add unit tests to vet this code better.

Drive-by fixes:

• Clear indirectCallEffects during --discard-global-effects, before recomputing global effects, and if a pass's addsEffects() is true. Clearing it when recomputing global effects is necessary to remove stale entries for types that no longer exist after type rewriting (although it should make no difference to optimizations).
• Fix use-after-free in tests due to static storage of HeapTypes / Types + destroyAllTypesForTestingPurposesOnly. The static HeapType / Type in getMutI8Array and similar functions referred to an index in globalHeapTypeStore / globalTupleStore, which gets cleared in unit tests with destroyAllTypesForTestingPurposesOnly(), causing the index to refer to garbage. Change these to not use static storage so that they're always in sync with globalHeapTypeStore / globalTupleStore.
• More changes to support gmock. NFC: Fix gmock integration in unit tests #8879 partially addressed this but I still hit some linker errors when adding new test code using gmock. The issue is that the earlier PR didn't change anything when BUILD_FUZZTEST is false.

[stevenfontanella]

Running a test against calcworker to confirm that the binary size savings return.

[stevenfontanella]

Running a test against calcworker to confirm that the binary size savings return.

The savings are more modest than before (1187 bytes), since before #8833 we were overly optimistic. I also tried with the other potential fix that I mentioned -- which is less conservative -- and only saves 5 additional bytes.