Add clang-cc option "-analyzer-experimental-checks" to enable experimental path-sensitive checks.  The idea is to separate "barely working" or "skunkworks" checks from ones that should always run.  Later we need more fine-grain checker control.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@87053 91177308-0d34-0410-b5e6-96231b3b80d8