split arithmetic_test into div/saturated. Fixes #2208

PiperOrigin-RevId: 638215809

Author: jan-wassenberg

BUILD

@@ -496,6 +496,7 @@ HWY_TESTS = [
     ("hwy/tests/", "count_test"),
     ("hwy/tests/", "crypto_test"),
     ("hwy/tests/", "demote_test"),
+    ("hwy/tests/", "div_test"),
     ("hwy/tests/", "dup128_vec_test"),
     ("hwy/tests/", "expand_test"),
     ("hwy/tests/", "float_test"),
@@ -517,6 +518,7 @@ HWY_TESTS = [
     ("hwy/tests/", "reduction_test"),
     ("hwy/tests/", "resize_test"),
     ("hwy/tests/", "reverse_test"),
+    ("hwy/tests/", "saturated_test"),
     ("hwy/tests/", "shift_test"),
     ("hwy/tests/", "shuffle4_test"),
     ("hwy/tests/", "slide_up_down_test"),

CMakeLists.txt

@@ -680,6 +680,7 @@ set(HWY_TEST_FILES
   hwy/tests/count_test.cc
   hwy/tests/crypto_test.cc
   hwy/tests/demote_test.cc
+  hwy/tests/div_test.cc
   hwy/tests/dup128_vec_test.cc
   hwy/tests/expand_test.cc
   hwy/tests/float_test.cc
@@ -701,6 +702,7 @@ set(HWY_TEST_FILES
   hwy/tests/reduction_test.cc
   hwy/tests/resize_test.cc
   hwy/tests/reverse_test.cc
+  hwy/tests/saturated_test.cc
   hwy/tests/shift_test.cc
   hwy/tests/shuffle4_test.cc
   hwy/tests/slide_up_down_test.cc