Make CompilationResult an aggregate in C++20.

Bug: chromium:1284275
Change-Id: Id429806b802282b7b045628fd8a3371618eb9f7f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3774123
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81842}

test/fuzzer/wasm-streaming.cc

@@ -18,8 +18,6 @@ namespace v8::internal::wasm {
 
 // Some properties of the compilation result to check. Extend if needed.
 struct CompilationResult {
-  MOVE_ONLY_WITH_DEFAULT_CONSTRUCTORS(CompilationResult);
-
   bool failed = false;
   std::string error_message;