Driver: tweak handling of '--analyze' to invoke

analyzer -cc1 options that are tailored to the
input type.  If the input type is "C++", we should
only run the dead stores checker (for now).  Similarly,
checks specific to Objective-C should only run
on Objective-C Code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123481 91177308-0d34-0410-b5e6-96231b3b80d8