Suppress a GCC -Wunused-variable warning in -Asserts builds

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175319 91177308-0d34-0410-b5e6-96231b3b80d8
Reinitialize the ivars in the subtarget.

When we're recalculating the feature set of the subtarget, we need to have the
ivars in their initial state.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175320 91177308-0d34-0410-b5e6-96231b3b80d8
Temporary revert of 175320.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175322 91177308-0d34-0410-b5e6-96231b3b80d8
Pacify -Wnon-virtual-dtor

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175324 91177308-0d34-0410-b5e6-96231b3b80d8