THRIFT-1814 Minor D library fixes
fix a few tiny issues in the D library so that it compiles using the upcoming 2.061 DMD release

Patch: David Nadlinger
diff --git a/lib/d/src/thrift/codegen/base.d b/lib/d/src/thrift/codegen/base.d
index d697375..95e09ff 100644
--- a/lib/d/src/thrift/codegen/base.d
+++ b/lib/d/src/thrift/codegen/base.d
@@ -913,7 +913,7 @@
   // combinations. Functionality checks are covered by the rest of the test
   // suite.
 
-  struct Test {
+  static struct Test {
     // Non-nullable.
     int a1;
     int a2;