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/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index ecd6ac4..a0a072b 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -1871,7 +1871,7 @@
   for (const MachineOperand &MO : Loc->operands()) {
     if (!MO.isReg())
       continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg)
       continue;
     if (MO.isUse()) {
@@ -1909,7 +1909,7 @@
       return Loc;
     if (!MO.isReg() || MO.isUse())
       continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg)
       continue;
     if (Uses.count(Reg)) {
@@ -1937,7 +1937,7 @@
   for (const MachineOperand &MO : PI->operands()) {
     if (!MO.isReg())
       continue;
-    unsigned Reg = MO.getReg();
+    Register Reg = MO.getReg();
     if (!Reg)
       continue;
     if (MO.isUse()) {
@@ -2010,7 +2010,7 @@
       }
       if (!MO.isReg())
         continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (!Reg)
         continue;
       if (MO.isDef()) {
@@ -2060,7 +2060,7 @@
     for (const MachineOperand &MO : TIB->operands()) {
       if (!MO.isReg() || !MO.isUse() || !MO.isKill())
         continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (!Reg)
         continue;
       if (!AllDefsSet.count(Reg)) {
@@ -2078,7 +2078,7 @@
     for (const MachineOperand &MO : TIB->operands()) {
       if (!MO.isReg() || !MO.isDef() || MO.isDead())
         continue;
-      unsigned Reg = MO.getReg();
+      Register Reg = MO.getReg();
       if (!Reg || Register::isVirtualRegister(Reg))
         continue;
       addRegAndItsAliases(Reg, TRI, ActiveDefsSet);