[analyzer] MallocChecker: Prevent Integer Set Library false positives Summary: Integer Set Library using retain-count based allocation which is not modeled in MallocChecker. Reviewed By: NoQ Tags: #clang Differential Revision: https://reviews.llvm.org/D64680 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@366391 91177308-0d34-0410-b5e6-96231b3b80d8