[wasm] Fix test generation for shared memory

R=gdeepti@chromium.org

Change-Id: I8fabe18101b7e23b5e2971fedd0bd3591783dc85
Reviewed-on: https://chromium-review.googlesource.com/c/1329699Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57441}

test/fuzzer/wasm-fuzzer-common.cc

@@ -183,7 +183,7 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
     }
     os << ", " << (module->mem_export ? "true" : "false");
     if (module->has_shared_memory) {
-      os << ", shared";
+      os << ", true";
     }
     os << ");\n";
   }