[analyzer] Malloc Checker: reduce false negatives rate by assuming that
a pointer cannot escape through calls to system functions. Also, stop
after reporting the first use-after-free.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150315 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed