Fix d8 prompt after readline removal

src/d8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 1373 matching lines @@
   v8::Local<v8::Context> context =
       v8::Local<v8::Context>::New(isolate, evaluation_context_);
   v8::Context::Scope context_scope(context);
   PerIsolateData::RealmScope realm_scope(PerIsolateData::Get(isolate));
   Local<String> name =
       String::NewFromUtf8(isolate, "(d8)", NewStringType::kNormal)
           .ToLocalChecked();
   printf("V8 version %s\n", V8::GetVersion());
   while (true) {
     HandleScope inner_scope(isolate);
-    printf(" d8>");
+    printf("d8> ");
 #if defined(__native_client__)
     // Native Client libc is used to being embedded in Chrome and
     // has trouble recognizing when to flush.
     fflush(stdout);
 #endif
     Local<String> input = Shell::ReadFromStdin(isolate);
     if (input.IsEmpty()) break;
     ExecuteString(isolate, input, name, true, true);
   }
   printf("\n");
@@ skipping 1049 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif