Make LLVMContext and LLVMContextImpl classes instead of structs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78690 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Archive/ArchiveInternals.h b/lib/Archive/ArchiveInternals.h
index 98f9c89..d187ed9 100644
--- a/lib/Archive/ArchiveInternals.h
+++ b/lib/Archive/ArchiveInternals.h
@@ -31,7 +31,7 @@
 
 namespace llvm {
 
-  struct LLVMContext;
+  class LLVMContext;
 
   /// The ArchiveMemberHeader structure is used internally for bitcode
   /// archives.