[analyzer] Malloc Checker: Report a leak when we are returning freed
memory.
(As per one test case, the existing checker thought that this could
cause a lot of false positives - not sure if that's valid, to be
verified.)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150313 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed