Through code search on file wasm-compiler.cc suspected CL is 
https://chromium.googlesource.com/v8/v8/+/76eb976a67273b8c03c744f64ad850b0432554b9

titzer@, could you please take a look and please help us to find correct owner if it is not related your changes.

ClusterFuzz has detected this issue as fixed in range 421457:421501.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5874089917153280

Fuzzer: afl_v8_wasm_code_fuzzer
Job Type: afl_chrome_asan
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000008
Crash State:
  v8::internal::compiler::WasmGraphBuilder::AppendToPhi
  v8::internal::wasm::WasmFullDecoder::CreateOrMergeIntoPhi
  v8::internal::wasm::WasmFullDecoder::BreakTo
  
Fixed: https://cluster-fuzz.appspot.com/revisions?job=afl_chrome_asan&range=421457:421501

Minimized Testcase (0.06 Kb): https://cluster-fuzz.appspot.com/download/AMIfv96Rp29onMc9frH6RpvRwP9Tz0Zx4FGSy3f_shXXfxBQCkEIRNdiNLHXzmX-8Fmdj6LajZligPL6pG-JuVC4a_Vg9_qQOb7fyL9u_eRVosuLusTxvFL75z7H-hc7SrEuAKbZxVe-OwQfKvlBdJTgv5rd6zqNLw?testcase_id=5874089917153280

See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase is verified as fixed, closing issue.

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