Make compilers agree on source position of thrown errors.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index 19662c44972da9aab22ccac15b45fdc3efedbc3f..89dc8751d1d98b2a1646f8770d4005498980b1cd 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -1620,9 +1620,10 @@ bool PositionsRecorder::WriteRecordedPositions() {
   }
 
   // Write the position if it is different from what was written last time and
-  // also different from the written statement position.
+  // also different from the statement position that was just written.
   if (state_.current_position != state_.written_position &&
-      state_.current_position != state_.written_statement_position) {
+      (state_.current_position != state_.written_statement_position ||
+       !written)) {
     EnsureSpace ensure_space(assembler_);
     assembler_->RecordRelocInfo(RelocInfo::POSITION, state_.current_position);
     state_.written_position = state_.current_position;