Re-enable av1_selfguided_restoration for ARM NEON.

Commit 0e07ea54da2e429c93f493185da6640dfd64e0d6 disabled
av1_apply_selfguided_restoration and av1_selfguided_restoration for ARM
NEON:
  https://aomedia-review.googlesource.com/c/aom/+/97703

Commit d65a573357a982dc28899e98beaaf02ccbb6052a re-enabled
av1_apply_selfguided_restoration but left av1_selfguided_restoration
disabled for ARM NEON:
  https://aomedia-review.googlesource.com/c/aom/+/104881

This CL reverts the rest of commit
0e07ea54da2e429c93f493185da6640dfd64e0d6.

BUG=b/141859709
BUG=b/141858830

Change-Id: Id2ef315297807054a4d9e71b9743324300353009
diff --git a/av1/common/av1_rtcd_defs.pl b/av1/common/av1_rtcd_defs.pl
index 3bd97cc..0a99f70 100644
--- a/av1/common/av1_rtcd_defs.pl
+++ b/av1/common/av1_rtcd_defs.pl
@@ -405,9 +405,7 @@
 add_proto qw/int av1_selfguided_restoration/, "const uint8_t *dgd8, int width, int height,
                                  int dgd_stride, int32_t *flt0, int32_t *flt1, int flt_stride,
                                  int sgr_params_idx, int bit_depth, int highbd";
-# TODO(b/141858830,b/141859709): neon is currently disabled due to use of
-# uninitialized memory.
-specialize qw/av1_selfguided_restoration sse4_1 avx2/;
+specialize qw/av1_selfguided_restoration sse4_1 avx2 neon/;
 
 # CONVOLVE_ROUND/COMPOUND_ROUND functions
 
diff --git a/test/selfguided_filter_test.cc b/test/selfguided_filter_test.cc
index 1f0db6b..d65cce5 100644
--- a/test/selfguided_filter_test.cc
+++ b/test/selfguided_filter_test.cc
@@ -213,9 +213,7 @@
     ::testing::Values(av1_apply_selfguided_restoration_avx2));
 #endif
 
-// TODO(b/141858830,b/141859709): neon is currently disabled due to use of
-// uninitialized memory.
-#if 0  // HAVE_NEON
+#if HAVE_NEON
 INSTANTIATE_TEST_SUITE_P(
     NEON, AV1SelfguidedFilterTest,
     ::testing::Values(av1_apply_selfguided_restoration_neon));