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

include/llvm/Analysis/ScalarEvolution.h

@@ -41,7 +41,7 @@ namespace llvm {
   class Type;
   class ScalarEvolution;
   class TargetData;
-  struct LLVMContext;
+  class LLVMContext;
   class Loop;
   class LoopInfo;
   class Operator;