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/AsmParser/LLLexer.h b/lib/AsmParser/LLLexer.h
index 667ab2c..de39272 100644
--- a/lib/AsmParser/LLLexer.h
+++ b/lib/AsmParser/LLLexer.h
@@ -24,7 +24,7 @@
   class MemoryBuffer;
   class Type;
   class SMDiagnostic;
-  struct LLVMContext;
+  class LLVMContext;
 
   class LLLexer {
     const char *CurPtr;