Remove unused private fields found by clang's new -Wunused-private-field.

There are some that I didn't remove this round because they looked like
obvious stubs. There are dead variables in gtest too, they should be
fixed upstream.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158090 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/PostRASchedulerList.cpp

@@ -78,7 +78,6 @@ AntiDepBreaker::~AntiDepBreaker() { }
 
 namespace {
   class PostRAScheduler : public MachineFunctionPass {
-    AliasAnalysis *AA;
     const TargetInstrInfo *TII;
     RegisterClassInfo RegClassInfo;