[cleanup] Remove or rewrite some of my old TODOs

These are either resolved (in which case I've removed them),
or never will be done (in which case I've reworded them in non-TODO terms).

Bug: v8:10933
Change-Id: I2e36df770cf2109974a790916172b6e1bace06fb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2432069Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70179}

src/ast/scopes.cc

@@ -1629,7 +1629,6 @@ const char* Header(ScopeType scope_type, FunctionKind function_kind,
                    bool is_declaration_scope) {
   switch (scope_type) {
     case EVAL_SCOPE: return "eval";
-    // TODO(adamk): Should we print concise method scopes specially?
     case FUNCTION_SCOPE:
       if (IsGeneratorFunction(function_kind)) return "function*";
       if (IsAsyncFunction(function_kind)) return "async function";

src/d8/d8.cc

@@ -714,7 +714,7 @@ std::string ToSTLString(Isolate* isolate, Local<String> v8_str) {
 
 bool IsAbsolutePath(const std::string& path) {
 #if defined(_WIN32) || defined(_WIN64)
-  // TODO(adamk): This is an incorrect approximation, but should
+  // This is an incorrect approximation, but should
   // work for all our test-running cases.
   return path.find(':') != std::string::npos;
 #else
@@ -725,7 +725,8 @@ bool IsAbsolutePath(const std::string& path) {
 std::string GetWorkingDirectory() {
 #if defined(_WIN32) || defined(_WIN64)
   char system_buffer[MAX_PATH];
-  // TODO(adamk): Support Unicode paths.
+  // Unicode paths are unsupported, which is fine as long as
+  // the test directory doesn't include any such paths.
   DWORD len = GetCurrentDirectoryA(MAX_PATH, system_buffer);
   CHECK_GT(len, 0);
   return system_buffer;

src/objects/value-serializer.cc

@@ -1642,7 +1642,6 @@ MaybeHandle<JSRegExp> ValueDeserializer::ReadJSRegExp() {
   }
 
   // Ensure the deserialized flags are valid.
-  // TODO(adamk): Can we remove this check now that dotAll is always-on?
   uint32_t flags_mask = static_cast<uint32_t>(-1) << JSRegExp::kFlagCount;
   if ((raw_flags & flags_mask) ||
       !JSRegExp::New(isolate_, pattern, static_cast<JSRegExp::Flags>(raw_flags))