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/Target/PowerPC/PPCFastISel.cpp b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
index 2954b02..f524bf5 100644
--- a/llvm/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFastISel.cpp
@@ -162,7 +162,7 @@
     bool PPCEmitCmp(const Value *Src1Value, const Value *Src2Value,
                     bool isZExt, unsigned DestReg,
                     const PPC::Predicate Pred);
-    bool PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
+    bool PPCEmitLoad(MVT VT, Register &ResultReg, Address &Addr,
                      const TargetRegisterClass *RC, bool IsZExt = true,
                      unsigned FP64LoadOpc = PPC::LFD);
     bool PPCEmitStore(MVT VT, unsigned SrcReg, Address &Addr);
@@ -451,7 +451,7 @@
 // Emit a load instruction if possible, returning true if we succeeded,
 // otherwise false.  See commentary below for how the register class of
 // the load is determined.
-bool PPCFastISel::PPCEmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
+bool PPCFastISel::PPCEmitLoad(MVT VT, Register &ResultReg, Address &Addr,
                               const TargetRegisterClass *RC,
                               bool IsZExt, unsigned FP64LoadOpc) {
   unsigned Opc;
@@ -612,7 +612,7 @@
   const TargetRegisterClass *RC =
     AssignedReg ? MRI.getRegClass(AssignedReg) : nullptr;
 
-  unsigned ResultReg = 0;
+  Register ResultReg = 0;
   if (!PPCEmitLoad(VT, ResultReg, Addr, RC, true,
       PPCSubTarget->hasSPE() ? PPC::EVLDD : PPC::LFD))
     return false;
@@ -1051,7 +1051,7 @@
   }
 
   const TargetRegisterClass *RC = &PPC::F8RCRegClass;
-  unsigned ResultReg = 0;
+  Register ResultReg = 0;
   if (!PPCEmitLoad(MVT::f64, ResultReg, Addr, RC, !IsSigned, LoadOpc))
     return 0;
 
@@ -1176,7 +1176,7 @@
   const TargetRegisterClass *RC =
     AssignedReg ? MRI.getRegClass(AssignedReg) : nullptr;
 
-  unsigned ResultReg = 0;
+  Register ResultReg = 0;
   if (!PPCEmitLoad(VT, ResultReg, Addr, RC, !IsSigned))
     return 0;
 
@@ -1717,7 +1717,7 @@
     if (const ConstantInt *CI = dyn_cast<ConstantInt>(RV)) {
       CCValAssign &VA = ValLocs[0];
 
-      unsigned RetReg = VA.getLocReg();
+      Register RetReg = VA.getLocReg();
       // We still need to worry about properly extending the sign. For example,
       // we could have only a single bit or a constant that needs zero
       // extension rather than sign extension. Make sure we pass the return
@@ -2353,7 +2353,7 @@
   if (!PPCComputeAddress(LI->getOperand(0), Addr))
     return false;
 
-  unsigned ResultReg = MI->getOperand(0).getReg();
+  Register ResultReg = MI->getOperand(0).getReg();
 
   if (!PPCEmitLoad(VT, ResultReg, Addr, nullptr, IsZExt,
         PPCSubTarget->hasSPE() ? PPC::EVLDD : PPC::LFD))