Fix uninitialized pointer members in Target/X86

[akshaykhadse]

Summary

This change fixes static analysis errors

[akshaykhadse]

Add other related files

[LuoYuanke]

LGTM

[LuoYuanke]

@akshaykhadse, do you want me to help to land the patch?

[akshaykhadse]

In D148312#4270771, @LuoYuanke wrote:

@akshaykhadse, do you want me to help to land the patch?

Yes, it would be great if you could land this one.

llvm/lib/Target/X86/X86FixupBWInsts.cpp

private:
   bool OptForSize = false;
 
   /// Machine loop info used for guiding some heruistics.
   MachineLoopInfo *MLI = nullptr;
 
   /// Register Liveness information after the current instruction.
   LivePhysRegs LiveRegs;
 
-  ProfileSummaryInfo *PSI;
-  MachineBlockFrequencyInfo *MBFI;
+  ProfileSummaryInfo *PSI = nullptr;
+  MachineBlockFrequencyInfo *MBFI = nullptr;
 };
 char FixupBWInstPass::ID = 0;
 }
 
 INITIALIZE_PASS(FixupBWInstPass, FIXUPBW_NAME, FIXUPBW_DESC, false, false)
 
 FunctionPass *llvm::createX86FixupBWInsts() { return new FixupBWInstPass(); }
 

llvm/lib/Target/X86/X86LoadValueInjectionLoadHardening.cpp

 
 private:
   using GraphBuilder = ImmutableGraphBuilder<MachineGadgetGraph>;
   using Edge = MachineGadgetGraph::Edge;
   using Node = MachineGadgetGraph::Node;
   using EdgeSet = MachineGadgetGraph::EdgeSet;
   using NodeSet = MachineGadgetGraph::NodeSet;
 
-  const X86Subtarget *STI;
-  const TargetInstrInfo *TII;
-  const TargetRegisterInfo *TRI;
+  const X86Subtarget *STI = nullptr;
+  const TargetInstrInfo *TII = nullptr;
+  const TargetRegisterInfo *TRI = nullptr;
 
   std::unique_ptr<MachineGadgetGraph>
   getGadgetGraph(MachineFunction &MF, const MachineLoopInfo &MLI,
                  const MachineDominatorTree &MDT,
                  const MachineDominanceFrontier &MDF) const;
   int hardenLoadsWithPlugin(MachineFunction &MF,
                             std::unique_ptr<MachineGadgetGraph> Graph) const;
   int hardenLoadsWithHeuristic(MachineFunction &MF,