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

Summary:
The getNumElements in base VectorType is being deprecated.

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

Reviewers: efriedma, tlively, fpetrogalli, c-rhodes, dschuff

Reviewed By: tlively, dschuff

Subscribers: dschuff, sbc100, tschuett, jgravelle-google, hiraditya, aheejin, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82217

Author: christetreault-llvm

llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp

@@ -63,10 +63,11 @@ unsigned WebAssemblyTTIImpl::getArithmeticInstrCost(
       // 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() *
+            (TargetTransformInfo::TCC_Basic +
+             getArithmeticInstrCost(Opcode, VTy->getElementType(), CostKind) +
+             TargetTransformInfo::TCC_Basic);
       break;
     }
   }