Add prelim error check for pointers in structs.

Bug: 2954471
Change-Id: Icacf67dd3eeb3dda67e1eae3d54e11f7efa6c680
diff --git a/slang_rs_backend.cpp b/slang_rs_backend.cpp
index 9fa4d98..c2d8305 100644
--- a/slang_rs_backend.cpp
+++ b/slang_rs_backend.cpp
@@ -121,7 +121,10 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 void RSBackend::HandleTranslationUnitPost(llvm::Module *M) {
-  mContext->processExport();
+  if (!mContext->processExport()) {
+    mDiags.Report(mDiags.getCustomDiagID(clang::Diagnostic::Error,
+                                         "elements cannot be exported"));
+  }
 
   // Dump export variable info
   if (mContext->hasExportVar()) {