THRIFT-3337 Add testBool method to cross tests

This closes #611
diff --git a/lib/c_glib/test/testthrifttestclient.cpp b/lib/c_glib/test/testthrifttestclient.cpp
index e1737cd..e618fe9 100755
--- a/lib/c_glib/test/testthrifttestclient.cpp
+++ b/lib/c_glib/test/testthrifttestclient.cpp
@@ -67,6 +67,10 @@
     out = thing;
   }
 
+  bool testBool(const bool thing) {
+    printf("[C -> C++] testBool(%s)\n", thing ? "true" : "false");
+    return thing;
+  }
   int8_t testByte(const int8_t thing) {
     printf("[C -> C++] testByte(%d)\n", (int)thing);
     return thing;