[SVE] Remove calls to VectorType::getNumElements from WebASM

[ctetreau]

Summary

The getNumElements in base VectorType is being deprecated.

See: http://lists.llvm.org/pipermail/llvm-dev/2020-March/139811.html

[dschuff]

The dependent revision in phabricator has the context, but please also add it to the commit description for this change (either directly or via a link) so that it will show up in git as well.

[tlively]

+1 to what Derek said :)

llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp

if (auto *VTy = dyn_cast<VectorType>(Ty)) {
     case Instruction::LShr:
     case Instruction::AShr:
     case Instruction::Shl:
       // SIMD128's shifts currently only accept a scalar shift count. For each
       // element, we'll need to extract, op, insert. The following is a rough
       // approxmation.
       if (Opd2Info != TTI::OK_UniformValue &&
           Opd2Info != TTI::OK_UniformConstantValue)
-        Cost = VTy->getNumElements() *
-               (TargetTransformInfo::TCC_Basic +
-                getArithmeticInstrCost(Opcode, VTy->getElementType(), CostKind) +
-                TargetTransformInfo::TCC_Basic);
+        Cost =
+            cast<FixedVectorType>(VTy)->getNumElements() *
       break;
     }
   }
   return Cost;
 }
 
 unsigned WebAssemblyTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
                                                 unsigned Index) {
   unsigned Cost = BasicTTIImplBase::getVectorInstrCost(Opcode, Val, Index);
 
   // SIMD128's insert/extract currently only take constant indices.
   if (Index == -1u)
     return Cost + 25 * TargetTransformInfo::TCC_Expensive;
 
   return Cost;
 }