[V8] Use previous token location as EOS token location

EOS token location is useless for users and messages.js are not ready for its location.
With this CL we use location of token before EOS for it.

LOG=Y
BUG=chromium:480652
R=yurys@chromium.org,yangguo@chromium.org

Review URL: https://codereview.chromium.org/1100993003

Cr-Commit-Position: refs/heads/master@{#28164}

src/scanner.cc

@@ -225,6 +225,10 @@ static const byte one_char_tokens[] = {
 
 
 Token::Value Scanner::Next() {
+  if (next_.token == Token::EOS) {
+    next_.location.beg_pos = current_.location.beg_pos;
+    next_.location.end_pos = current_.location.end_pos;
+  }
   current_ = next_;
   has_line_terminator_before_next_ = false;
   has_multiline_comment_before_next_ = false;

test/cctest/test-api.cc

@@ -12565,6 +12565,18 @@ THREADED_TEST(TryCatchSourceInfo) {
 }
 
 
+THREADED_TEST(TryCatchSourceInfoForEOSError) {
+  LocalContext context;
+  v8::HandleScope scope(context->GetIsolate());
+  v8::TryCatch try_catch;
+  v8::Script::Compile(v8_str("!\n"));
+  CHECK(try_catch.HasCaught());
+  v8::Handle<v8::Message> message = try_catch.Message();
+  CHECK_EQ(1, message->GetLineNumber());
+  CHECK_EQ(0, message->GetStartColumn());
+}
+
+
 THREADED_TEST(CompilationCache) {
   LocalContext context;
   v8::HandleScope scope(context->GetIsolate());