Remove unused methods and ivars.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173284 91177308-0d34-0410-b5e6-96231b3b80d8
Initialize SSPBufferSize. PR14999. Patch by Vinson Lee.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173285 91177308-0d34-0410-b5e6-96231b3b80d8