String:WriteUtf8: Add REPLACE_INVALID_UTF8 option

test/cctest/test-parsing.cc

Index: test/cctest/test-parsing.cc
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index e53250def93322a9e965ac0b2be1455856375e47..7967e02b7ea2cf577ffe7683bcf82c93de566d3a 100644
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -580,7 +580,8 @@ TEST(Utf8CharacterStream) {
   for (int i = 0; i <= kMaxUC16Char; i++) {
     cursor += unibrow::Utf8::Encode(buffer + cursor,
                                     i,
-                                    unibrow::Utf16::kNoPreviousCharacter);
+                                    unibrow::Utf16::kNoPreviousCharacter,
+                                    true);
   }
   ASSERT(cursor == kAllUtf8CharsSizeU);