Codegen pass definition cleanup. No functionality.

Moving toward a uniform style of pass definition to allow easier target configuration.
Globally declare Pass ID.
Globally declare pass initializer.
Use INITIALIZE_PASS consistently.
Add a call to the initializer from CodeGen.cpp.
Remove redundant "createPass" functions and "getPassName" methods.

While cleaning up declarations, cleaned up comments (sorry for large diff).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150100 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index bbc0f18..e058376 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -170,7 +170,6 @@
     }
 
     virtual bool runOnMachineFunction(MachineFunction &MF);
-    virtual const char *getPassName() const { return "If Converter"; }
 
   private:
     bool ReverseBranchCondition(BBInfo &BBI);
@@ -253,12 +252,12 @@
   char IfConverter::ID = 0;
 }
 
+char &llvm::IfConverterID = IfConverter::ID;
+
 INITIALIZE_PASS_BEGIN(IfConverter, "if-converter", "If Converter", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
 INITIALIZE_PASS_END(IfConverter, "if-converter", "If Converter", false, false)
 
-FunctionPass *llvm::createIfConverterPass() { return new IfConverter(); }
-
 bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
   TLI = MF.getTarget().getTargetLowering();
   TII = MF.getTarget().getInstrInfo();