[CodeGen] Have a special function to get TBAA info for may-alias accesses

This is part of D37826 reworked to be a separate patch to
simplify review.

Differential Revision: https://reviews.llvm.org/D38408

llvm-svn: 314660
diff --git a/clang/lib/CodeGen/CodeGenTBAA.h b/clang/lib/CodeGen/CodeGenTBAA.h
index 9ff9e88..71c53d43 100644
--- a/clang/lib/CodeGen/CodeGenTBAA.h
+++ b/clang/lib/CodeGen/CodeGenTBAA.h
@@ -116,6 +116,10 @@
 
   /// Get the scalar tag MDNode for a given scalar type.
   llvm::MDNode *getTBAAScalarTagInfo(llvm::MDNode *AccessNode);
+
+  /// getMayAliasTypeInfo - Get TBAA information that represents may-alias
+  /// accesses.
+  llvm::MDNode *getMayAliasTypeInfo();
 };
 
 }  // end namespace CodeGen