Added TargetPassConfig. The first little step toward configuring codegen passes.

Allows command line overrides to be centralized in LLVMTargetMachine.cpp.
LLVMTargetMachine can intercept common passes and give precedence to command line overrides.
Allows adding "internal" target configuration options without touching TargetOptions.
Encapsulates the PassManager.
Provides a good point to initialize all CodeGen passes so that Pass ID's can be used in APIs.
Allows modifying the target configuration hooks without rebuilding the world.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149672 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/XCore/XCoreTargetMachine.h

@@ -56,7 +56,8 @@ public:
   virtual const TargetData       *getTargetData() const { return &DataLayout; }
 
   // Pass Pipeline Configuration
-  virtual bool addInstSelector(PassManagerBase &PM);
+  virtual TargetPassConfig *createPassConfig(PassManagerBase &PM,
+                                             bool DisableVerify);
 };
 
 } // end namespace llvm