Add configuration plumbing to enable static initializer branching in the CFG for the analyzer.

This setting still isn't enabled yet in the analyzer.  This is
just prep work.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178317 91177308-0d34-0410-b5e6-96231b3b80d8
Add static analyzer support for conditionally executing static initializers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178318 91177308-0d34-0410-b5e6-96231b3b80d8