Thrift: Change docstring syntax.

Summary:
The old docstring syntax collided with the syntax for list constants.
The new syntax looks a lot like doxygent comments.

Trac Bug: #4664

Blame Rev: 32392

Reviewed By: mcslee

Test Plan:
../compiler/cpp/thrift -cpp DocTest.thrift
(with dump_docs on)
and looked at the output.
Generated C++ is identical to installed thrift.

Revert Plan: ok


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665182 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/thrifty.yy b/compiler/cpp/src/thrifty.yy
index ce11bf8..68384be 100644
--- a/compiler/cpp/src/thrifty.yy
+++ b/compiler/cpp/src/thrifty.yy
@@ -361,7 +361,7 @@
   tok_doctext
     {
       pdebug("DocTextOptional -> tok_doctext");
-      $$ = $1;
+      $$ = clean_up_doctext($1);
     }
 |
     {