Rename SVal::isType functions to SVal::isKind

Post-commit CR feedback from Jordan Rose regarding r175594.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175676 91177308-0d34-0410-b5e6-96231b3b80d8
Use op-> directly rather than via Optional<T>::getPointer.

Post-commit CR feedback from Jordan Rose regarding r175594.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175677 91177308-0d34-0410-b5e6-96231b3b80d8
Remove redundant Optional type in favor of llvm::Optional

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175678 91177308-0d34-0410-b5e6-96231b3b80d8
Include llvm::Optional in clang/Basic/LLVM.h

Post-commit CR feedback from Jordan Rose regarding r175594.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175679 91177308-0d34-0410-b5e6-96231b3b80d8