Fix a tiny test-only leak, found by LSan.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@207137 91177308-0d34-0410-b5e6-96231b3b80d8
MicrosoftVTableContext: Don't leak VPtrInfos. Found by LSan, PR19522.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@207138 91177308-0d34-0410-b5e6-96231b3b80d8