THRIFT-5855: cpp fuzzers

Add fuzzers for cpp support, to improve the reliability/robustness of the implementation
diff --git a/configure.ac b/configure.ac
index 8147a0b..4f55aad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -773,6 +773,7 @@
   lib/cl/Makefile
   lib/cpp/Makefile
   lib/cpp/test/Makefile
+  lib/cpp/test/fuzz/Makefile
   lib/cpp/thrift-nb.pc
   lib/cpp/thrift-z.pc
   lib/cpp/thrift-qt5.pc