[webassembly] 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).

Reviewers: aheejin

Subscribers: 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 for whole review: https://reviews.llvm.org/D65962

llvm-svn: 368627
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
index 7d8e86d..c18d604 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
@@ -358,7 +358,7 @@
   // Add the register which will be used to tell the jump table which block to
   // jump to.
   MachineRegisterInfo &MRI = MF.getRegInfo();
-  unsigned Reg = MRI.createVirtualRegister(&WebAssembly::I32RegClass);
+  Register Reg = MRI.createVirtualRegister(&WebAssembly::I32RegClass);
   MIB.addReg(Reg);
 
   // Compute the indices in the superheader, one for each bad block, and