test: move uint256_tests/operator_with_self to arith_uint256_tests

move/formatting-only change.

These tests do not cover uint256, so move them to the appropriate
test suite. Additionally, apply clang-format suggestions.

Author: stickies-v

src/test/arith_uint256_tests.cpp

@@ -578,4 +578,34 @@ BOOST_AUTO_TEST_CASE(conversion)
     }
 }
 
+BOOST_AUTO_TEST_CASE(operator_with_self)
+{
+    /* Clang 16 and earlier detects v -= v and v /= v as self-assignments
+       to 0 and 1 respectively.
+       See: https://github.com/llvm/llvm-project/issues/42469
+       and the fix in commit c5302325b2a62d77cf13dd16cd5c19141862fed0 .
+
+       This makes some sense for arithmetic classes, but could be considered a bug
+       elsewhere. Disable the warning here so that the code can be tested, but the
+       warning should remain on as there will likely always be a better way to
+       express this.
+    */
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wself-assign-overloaded"
+#endif
+    arith_uint256 v{2};
+    v *= v;
+    BOOST_CHECK_EQUAL(v, arith_uint256{4});
+    v /= v;
+    BOOST_CHECK_EQUAL(v, arith_uint256{1});
+    v += v;
+    BOOST_CHECK_EQUAL(v, arith_uint256{2});
+    v -= v;
+    BOOST_CHECK_EQUAL(v, arith_uint256{0});
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+}
+
 BOOST_AUTO_TEST_SUITE_END()

src/test/uint256_tests.cpp

@@ -2,7 +2,6 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <arith_uint256.h>
 #include <streams.h>
 #include <test/util/setup_common.h>
 #include <uint256.h>
@@ -245,38 +244,6 @@ BOOST_AUTO_TEST_CASE(methods) // GetHex SetHexDeprecated FromHex begin() end() s
     ss.clear();
 }
 
-BOOST_AUTO_TEST_CASE( operator_with_self )
-{
-
-/* Clang 16 and earlier detects v -= v and v /= v as self-assignments
-   to 0 and 1 respectively.
-   See: https://github.com/llvm/llvm-project/issues/42469
-   and the fix in commit c5302325b2a62d77cf13dd16cd5c19141862fed0 .
-
-   This makes some sense for arithmetic classes, but could be considered a bug
-   elsewhere. Disable the warning here so that the code can be tested, but the
-   warning should remain on as there will likely always be a better way to
-   express this.
-*/
-
-#if defined(__clang__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wself-assign-overloaded"
-#endif
-    arith_uint256 v{2};
-    v *= v;
-    BOOST_CHECK_EQUAL(v, arith_uint256{4});
-    v /= v;
-    BOOST_CHECK_EQUAL(v, arith_uint256{1});
-    v += v;
-    BOOST_CHECK_EQUAL(v, arith_uint256{2});
-    v -= v;
-    BOOST_CHECK_EQUAL(v, arith_uint256{0});
-#if defined(__clang__)
-#    pragma clang diagnostic pop
-#endif
-}
-
 /**
  * Implemented as a templated function so it can be reused by other classes that have a FromHex()
  * method that wraps base_blob::FromHex(), such as transaction_identifier::FromHex().