src: use V8 API for string conversion in inspector

Remove use of Intl in inspector code so that compiling without Intl does
not require disabling the inspector.

Author: Trott

src/inspector/main_thread_interface.cc

@@ -5,8 +5,6 @@
 #include "v8-inspector.h"
 #include "util-inl.h"
 
-#include <unicode/unistr.h>
-
 #include <functional>
 #include <memory>
 
@@ -289,10 +287,20 @@ Deletable* MainThreadInterface::GetObjectIfExists(int id) {
 }
 
 std::unique_ptr<StringBuffer> Utf8ToStringView(const std::string& message) {
-  icu::UnicodeString utf16 = icu::UnicodeString::fromUTF8(
-      icu::StringPiece(message.data(), message.length()));
-  StringView view(reinterpret_cast<const uint16_t*>(utf16.getBuffer()),
-                  utf16.length());
+  v8::Isolate* isolate = v8::Isolate::TryGetCurrent();
+  CHECK_NOT_NULL(isolate);
+
+  v8::Local<v8::String> myString =
+    v8::String::NewFromUtf8(isolate,
+                            message.data(),
+                            v8::NewStringType::kNormal,
+                            message.length()).ToLocalChecked();
+
+  // Length()+1 to account for null terminator
+  auto buffer = std::make_unique<uint16_t[]>(myString->Length()+1);
+  myString->Write(isolate, buffer.get());
+  StringView view(buffer.get(), myString->Length());
+
   return StringBuffer::create(view);
 }