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).

llvm-svn: 150100

llvm/lib/CodeGen/MachineSink.cpp

@@ -102,6 +102,7 @@ namespace {
 } // end anonymous namespace
 
 char MachineSinking::ID = 0;
+char &llvm::MachineSinkingID = MachineSinking::ID;
 INITIALIZE_PASS_BEGIN(MachineSinking, "machine-sink",
                 "Machine code sinking", false, false)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
@@ -110,8 +111,6 @@ INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_END(MachineSinking, "machine-sink",
                 "Machine code sinking", false, false)
 
-FunctionPass *llvm::createMachineSinkingPass() { return new MachineSinking(); }
-
 bool MachineSinking::PerformTrivialForwardCoalescing(MachineInstr *MI,
                                                      MachineBasicBlock *MBB) {
   if (!MI->isCopy())