Add Apple's Accelerate framework as a sparse linear algebra library.

- Currently DynamicSparseNormalCholeskySolver is unsupported for
  Accelerate.

Change-Id: I03b5a86bb22fef249c4aecd48947a613e8eff7a5

bazel/ceres.bzl

@@ -29,6 +29,7 @@
 # Support for building Ceres Solver with a specific configuration.
 
 CERES_SRCS = ["internal/ceres/" + filename for filename in [
+    "accelerate_sparse.cc",
     "array_utils.cc",
     "blas.cc",
     "block_evaluate_preparer.cc",
@@ -190,9 +191,11 @@ def ceres_library(name,
         # TODO(keir): These defines are placeholders for now to facilitate getting
         # started with a Bazel build. However, these should become configurable as
         # part of a Skylark Ceres target macro.
+        # https://github.com/ceres-solver/ceres-solver/issues/396
         defines = [
             "CERES_NO_SUITESPARSE",
             "CERES_NO_CXSPARSE",
+            "CERES_NO_ACCELERATE_SPARSE",
             "CERES_NO_LAPACK",
             "CERES_USE_EIGEN_SPARSE",
             "CERES_USE_CXX11_THREADS",