Unpin V8 (#5277)

* Do not compare reference values across executions

Since we optimize assuming a closed world, optimizations can change the types
and structure of GC data even in externally-visible ways. Because differences
are expected, the fuzzer already did not compare reference-typed values from
before and after optimizations when running with nominal typing. Update it to
not compare these values under any type system.

* Unpin V8

Our WasmGC output is no longer compatible with the previously pinned version and
the issue that caused us to pin it in the first place has been resolved.

Author: tlively

scripts/test/shared.py

@@ -202,9 +202,7 @@ def is_exe(fpath):
 NODEJS = os.getenv('NODE', which('node') or which('nodejs'))
 MOZJS = which('mozjs') or which('spidermonkey')
 
-# TODO: Remove the specific v8 version once we implement structref and can run
-# on recent v8.
-V8 = which('v8-10.8.104') or which('v8') or which('d8')
+V8 = which('v8') or which('d8')
 
 BINARYEN_INSTALL_DIR = os.path.dirname(options.binaryen_bin)
 WASM_OPT = [os.path.join(options.binaryen_bin, 'wasm-opt')]