ASTContext.h: replace include by a forward declaration.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161186 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/ASTContext.h b/include/clang/AST/ASTContext.h
index a8b00a7..37a86db 100644
--- a/include/clang/AST/ASTContext.h
+++ b/include/clang/AST/ASTContext.h
@@ -20,7 +20,6 @@
 #include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/VersionTuple.h"
-#include "clang/AST/Comment.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/LambdaMangleContext.h"
 #include "clang/AST/NestedNameSpecifier.h"
@@ -81,6 +80,10 @@
 
   namespace Builtin { class Context; }
 
+  namespace comments {
+    class FullComment;
+  }
+
 /// ASTContext - This class holds long-lived AST nodes (such as types and
 /// decls) that can be referred to throughout the semantic analysis of a file.
 class ASTContext : public RefCountedBase<ASTContext> {
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index edcfe8e..1c0c0c4 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/CharUnits.h"
+#include "clang/AST/Comment.h"
 #include "clang/AST/CommentLexer.h"
 #include "clang/AST/CommentSema.h"
 #include "clang/AST/CommentParser.h"