[mlir] Remove unused ConvertToLLVMPattern::linearizeSubscripts().

mlir/include/mlir/Conversion/StandardToLLVM/ConvertStandardToLLVM.h

protected:
 
   /// Get the MLIR type wrapping the LLVM i8* type.
   LLVM::LLVMType getVoidPtrType() const;
 
   /// Create an LLVM dialect operation defining the given index constant.
   Value createIndexConstant(ConversionPatternRewriter &builder, Location loc,
                             uint64_t value) const;
 
-  // Given subscript indices and array sizes in row-major order,
-  //   i_n, i_{n-1}, ..., i_1
-  //   s_n, s_{n-1}, ..., s_1
-  // obtain a value that corresponds to the linearized subscript
-  //   \sum_k i_k * \prod_{j=1}^{k-1} s_j
-  // by accumulating the running linearized value.
-  // Note that `indices` and `allocSizes` are passed in the same order as they
-  // appear in load/store operations and memref type declarations.
-  Value linearizeSubscripts(ConversionPatternRewriter &builder, Location loc,
-                            ArrayRef<Value> indices,
-                            ArrayRef<Value> allocSizes) const;
-
   // This is a strided getElementPtr variant that linearizes subscripts as:
   //   `base_offset + index_0 * stride_0 + ... + index_n * stride_n`.
   Value getStridedElementPtr(Location loc, Type elementTypePtr,
                              Value descriptor, ValueRange indices,
                              ArrayRef<int64_t> strides, int64_t offset,
                              ConversionPatternRewriter &rewriter) const;
 
   /// Returns if the givem memref type is supported.

mlir/lib/Conversion/StandardToLLVM/StandardToLLVM.cpp

LLVM::LLVMType ConvertToLLVMPattern::getVoidPtrType() const {
   return LLVM::LLVMType::getInt8PtrTy(&typeConverter.getContext());
 }
 
 Value ConvertToLLVMPattern::createIndexConstant(
     ConversionPatternRewriter &builder, Location loc, uint64_t value) const {
   return createIndexAttrConstant(builder, loc, getIndexType(), value);
 }
 
-Value ConvertToLLVMPattern::linearizeSubscripts(
-    ConversionPatternRewriter &builder, Location loc, ArrayRef<Value> indices,
-    ArrayRef<Value> allocSizes) const {
-  assert(indices.size() == allocSizes.size() &&
-         "mismatching number of indices and allocation sizes");
-  assert(!indices.empty() && "cannot linearize a 0-dimensional access");
-
-  Value linearized = indices.front();
-  for (int i = 1, nSizes = allocSizes.size(); i < nSizes; ++i) {
-    linearized = builder.create<LLVM::MulOp>(
-        loc, this->getIndexType(), ArrayRef<Value>{linearized, allocSizes[i]});
-    linearized = builder.create<LLVM::AddOp>(
-        loc, this->getIndexType(), ArrayRef<Value>{linearized, indices[i]});
-  }
-  return linearized;
-}
-
 Value ConvertToLLVMPattern::getStridedElementPtr(
     Location loc, Type elementTypePtr, Value descriptor, ValueRange indices,
     ArrayRef<int64_t> strides, int64_t offset,
     ConversionPatternRewriter &rewriter) const {
   MemRefDescriptor memRefDescriptor(descriptor);
 
   Value base = memRefDescriptor.alignedPtr(rewriter, loc);
   Value offsetValue = offset == MemRefType::getDynamicStrideOrOffset()