[mlir] Remove unused header include.

[akuegel]

Summary

Also adjust BUILD.bazel and remove an unused dependency.

[bkramer]

Thanks

mlir/test/lib/Dialect/Math/TestAlgebraicSimplification.cpp

 //===- TestAlgebraicSimplification.cpp - Test algebraic simplification ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains test passes for algebraic simplification patterns.
 //
 //===----------------------------------------------------------------------===//
 
-#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/Dialect/Math/IR/Math.h"
 #include "mlir/Dialect/Math/Transforms/Passes.h"
 #include "mlir/Dialect/Vector/VectorOps.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
 
 using namespace mlir;
 

utils/bazel/llvm-project-overlay/mlir/test/BUILD.bazel

 )
 
 cc_library(
     name = "TestMath",
     srcs = glob(["lib/Dialect/Math/*.cpp"]),
     defines = ["MLIR_CUDA_CONVERSIONS_ENABLED"],
     includes = ["lib/Dialect/Test"],
     deps = [
-        "//mlir:LLVMDialect",
         "//mlir:MathDialect",
         "//mlir:MathTransforms",
         "//mlir:Pass",
         "//mlir:TransformUtils",
         "//mlir:VectorOps",
     ],
 )