THRIFT-1624. java: Isset Generated differently on different platforms

This patch initializes is_union_ to a specific value to try and avoid the issue.

Patch: Brian Bloniarz

git-svn-id: https://svn.apache.org/repos/asf/thrift/trunk@1353784 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/parse/t_struct.h b/compiler/cpp/src/parse/t_struct.h
index aeee112..b82933d 100644
--- a/compiler/cpp/src/parse/t_struct.h
+++ b/compiler/cpp/src/parse/t_struct.h
@@ -43,11 +43,13 @@
   t_struct(t_program* program) :
     t_type(program),
     is_xception_(false),
+    is_union_(false),
     xsd_all_(false) {}
 
   t_struct(t_program* program, const std::string& name) :
     t_type(program, name),
     is_xception_(false),
+    is_union_(false),
     xsd_all_(false) {}
 
   void set_name(const std::string& name) {