[LegacyPassManager] Remove TargetMachine constructors

This provides a new way to access the TargetMachine through
TargetPassConfig, as a dependency.

The patterns replaced here are:

* Passes handling a null TargetMachine call
  `getAnalysisIfAvailable<TargetPassConfig>`.

* Passes not handling a null TargetMachine
  `addRequired<TargetPassConfig>` and call
  `getAnalysis<TargetPassConfig>`.

* MachineFunctionPasses now use MF.getTarget().

* Remove all the TargetMachine constructors.
* Remove INITIALIZE_TM_PASS.

This fixes a crash when running `llc -start-before prologepilog`.

PEI needs StackProtector, which gets constructed without a TargetMachine
by the pass manager. The StackProtector pass doesn't handle the case
where there is no TargetMachine, so it segfaults.

Related to PR30324.

Differential Revision: https://reviews.llvm.org/D33222

llvm-svn: 303360
diff --git a/llvm/lib/Target/AMDGPU/R600Packetizer.cpp b/llvm/lib/Target/AMDGPU/R600Packetizer.cpp
index 5b6dd1e..3e95712 100644
--- a/llvm/lib/Target/AMDGPU/R600Packetizer.cpp
+++ b/llvm/lib/Target/AMDGPU/R600Packetizer.cpp
@@ -36,7 +36,7 @@
 
 public:
   static char ID;
-  R600Packetizer(const TargetMachine &TM) : MachineFunctionPass(ID) {}
+  R600Packetizer() : MachineFunctionPass(ID) {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesCFG();
@@ -404,6 +404,6 @@
 
 } // end anonymous namespace
 
-llvm::FunctionPass *llvm::createR600Packetizer(TargetMachine &tm) {
-  return new R600Packetizer(tm);
+llvm::FunctionPass *llvm::createR600Packetizer() {
+  return new R600Packetizer();
 }