[profiler] Quick-fix for illegal source positions

For some unknown reasons, the profiler starts seeing illegal source
positions (see referenced bug).

This CL quick-fixes that by just ignoring them for now. This might
regress profiling, and should be fixed mid-term.

R=mstarzinger@chromium.org

Bug: chromium:953309
Change-Id: I10db7e5ad24e8470e319fc9418cd3a684f614c26
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1569845
Auto-Submit: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60895}

src/profiler/profiler-listener.cc

@@ -124,6 +124,10 @@ void ProfilerListener::CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
       int position = it.source_position().ScriptOffset();
       int line_number = script->GetLineNumber(position) + 1;
       int inlining_id = it.source_position().InliningId();
+
+      // TODO(953309): Fix this.
+      if (line_number == 0) continue;
+
       line_table->SetPosition(it.code_offset(), line_number, inlining_id);
 
       if (inlining_id != SourcePosition::kNotInlined) {