Revert "Give internal classes hidden visibility."

It works with clang, but GCC has different rules so we can't make all of those
hidden. This reverts commit r190534.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190536 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AntiDepBreaker.h b/lib/CodeGen/AntiDepBreaker.h
index b6e5450..df47f98 100644
--- a/lib/CodeGen/AntiDepBreaker.h
+++ b/lib/CodeGen/AntiDepBreaker.h
@@ -28,7 +28,7 @@
 /// AntiDepBreaker - This class works into conjunction with the
 /// post-RA scheduler to rename registers to break register
 /// anti-dependencies.
-class LLVM_LIBRARY_VISIBILITY AntiDepBreaker {
+class AntiDepBreaker {
 public:
   typedef std::vector<std::pair<MachineInstr *, MachineInstr *> > 
     DbgValueVector;