[NFC] Remove no longer needed v8 flag to avoid warnings (#7297)

Recent v8 prints "warning: unrecognized flag" about it.

This warning broke a test. Add some logging to the test as well, to make
it easier to debug in the future.

Author: kripken

scripts/fuzz_opt.py

@@ -1718,7 +1718,10 @@ def handle(self, wasm):
         # Make sure that fuzz_shell.js actually executed all exports from both
         # wasm files.
         exports = get_exports(wasm, ['func']) + get_exports(second_wasm, ['func'])
-        assert output.count(FUZZ_EXEC_CALL_PREFIX) == len(exports)
+        calls_in_output = output.count(FUZZ_EXEC_CALL_PREFIX)
+        if calls_in_output == 0:
+            print(f'warning: no calls in output. output:\n{output}')
+        assert calls_in_output == len(exports)
 
         output = fix_output(output)
 

scripts/test/shared.py

@@ -255,7 +255,6 @@ def has_shell_timeout():
 V8_OPTS = [
     '--wasm-staging',
     '--experimental-wasm-compilation-hints',
-    '--experimental-wasm-memory64',
     '--experimental-wasm-stringref',
     '--experimental-wasm-fp16',
 ]