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/AsmParser/LLLexer.h b/lib/AsmParser/LLLexer.h
index 5dfb2be..85703c7 100644
--- a/lib/AsmParser/LLLexer.h
+++ b/lib/AsmParser/LLLexer.h
@@ -26,7 +26,7 @@
   class SMDiagnostic;
   class LLVMContext;
 
-  class LLVM_LIBRARY_VISIBILITY LLLexer {
+  class LLLexer {
     const char *CurPtr;
     MemoryBuffer *CurBuf;
     SMDiagnostic &ErrorInfo;