Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM

Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
diff --git a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index 444f618..18fcee6 100644
--- a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -232,7 +232,7 @@
   if (!MO.isReg() || !MO.isImplicit())
     return false;
 
-  unsigned Reg = MO.getReg();
+  Register Reg = MO.getReg();
   if (Reg == 0)
     return false;
 
@@ -252,7 +252,7 @@
     if (!MO.isReg()) continue;
     if ((MO.isDef() && MI.isRegTiedToUseOperand(i)) ||
         IsImplicitDefUse(MI, MO)) {
-      const unsigned Reg = MO.getReg();
+      const Register Reg = MO.getReg();
       for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
            SubRegs.isValid(); ++SubRegs)
         PassthruRegs.insert(*SubRegs);
@@ -365,7 +365,7 @@
   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
     MachineOperand &MO = MI.getOperand(i);
     if (!MO.isReg() || !MO.isDef()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (Reg == 0) continue;
 
     HandleLastUse(Reg, Count + 1, "", "\tDead Def: ", "\n");
@@ -375,7 +375,7 @@
   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
     MachineOperand &MO = MI.getOperand(i);
     if (!MO.isReg() || !MO.isDef()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (Reg == 0) continue;
 
     LLVM_DEBUG(dbgs() << " " << printReg(Reg, TRI) << "=g"
@@ -418,7 +418,7 @@
   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
     MachineOperand &MO = MI.getOperand(i);
     if (!MO.isReg() || !MO.isDef()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (Reg == 0) continue;
     // Ignore KILLs and passthru registers for liveness...
     if (MI.isKill() || (PassthruRegs.count(Reg) != 0))
@@ -471,7 +471,7 @@
   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
     MachineOperand &MO = MI.getOperand(i);
     if (!MO.isReg() || !MO.isUse()) continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (Reg == 0) continue;
 
     LLVM_DEBUG(dbgs() << " " << printReg(Reg, TRI) << "=g"
@@ -506,7 +506,7 @@
     for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
       MachineOperand &MO = MI.getOperand(i);
       if (!MO.isReg()) continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (Reg == 0) continue;
 
       if (FirstReg != 0) {