Add back a couple checks removed by r129128; the fact that an intitializer

is an array of structures doesn't imply it's a ConstantArray of
ConstantStruct.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129207 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/GlobalOpt/2011-04-09-EmptyGlobalCtors.ll

@@ -0,0 +1,5 @@
+; RUN: opt < %s -globalopt -disable-output
+
+%0 = type { i32, void ()* }
+@llvm.global_ctors = appending global [0 x %0] zeroinitializer
+