Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.
Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.

llvm-svn: 85042
diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index a0d3a24..3000bfe 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -70,7 +70,7 @@
 using namespace llvm;
 
 namespace {  // Anonymous namespace for class
-  struct VISIBILITY_HIDDEN PreVerifier : public FunctionPass {
+  struct PreVerifier : public FunctionPass {
     static char ID; // Pass ID, replacement for typeid
 
     PreVerifier() : FunctionPass(&ID) { }