[ASan] turn on leak checking for ASan tests and fix a few discovered leaks

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@190274 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer] Use generic configs for running sanitizer_common unit tests

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@190276 91177308-0d34-0410-b5e6-96231b3b80d8