[ItaniumMangle] Fix mangling of GNU __null in an expression to match GCC

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: erik.pilkington, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68368

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374013 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed