[turbofan]: Small visualizer cleanup and fix for string handling

src/ostreams.cc

Index: src/ostreams.cc
diff --git a/src/ostreams.cc b/src/ostreams.cc
index 4f28141d71aa4667bafd7f4742d97d26b5587636..b11332dafc521f62d423890224e0d23e64e832af 100644
--- a/src/ostreams.cc
+++ b/src/ostreams.cc
@@ -70,7 +70,6 @@ std::ostream& operator<<(std::ostream& os, const AsEscapedUC16ForJSON& c) {
   if (c.value == '\n') return os << "\\n";
   if (c.value == '\r') return os << "\\r";
   if (c.value == '\"') return os << "\\\"";
-  if (c.value == '\'') return os << "\\\'";
   return PrintUC16(os, c.value, IsOK);
 }