Correctly initialize the PrimaryBaseInfo if a base is null. Fixes PR5832.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91748 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGenCXX/virtual-function-calls.cpp b/test/CodeGenCXX/virtual-function-calls.cpp
index b927dec..0b3a684 100644
--- a/test/CodeGenCXX/virtual-function-calls.cpp
+++ b/test/CodeGenCXX/virtual-function-calls.cpp
@@ -9,3 +9,11 @@
   // CHECK: call void %
   a->f('c');
 }
+
+struct B : virtual A { 
+  virtual void f();
+};
+
+void f(B * b) {
+  b->f();
+}
\ No newline at end of file