Merge bitcoin/bitcoin#32588: util: Abort on failing CHECK_NONFATAL in debug builds

fa37153288 util: Abort on failing CHECK_NONFATAL in debug builds (MarcoFalke)
fa0dc4bdff test: Allow testing of check failures (MarcoFalke)
faeb58fe66 refactor: Set G_ABORT_ON_FAILED_ASSUME when G_FUZZING_BUILD (MarcoFalke)

Pull request description:

  A failing `CHECK_NONFATAL` will throw an exception. This is fine and even desired in production builds, because the program may catch the exception and give the user a way to easily report the bug upstream.

  However, in debug development builds, exceptions for internal bugs are problematic:

  * The exception could accidentally be caught and silently ignored
  * The exception does not include a full stacktrace, possibly making debugging harder

  Fix all issues by turning the exception into an abort in debug builds.

  This can be tested by reverting the hunks to `src/rpc/node.cpp` and `test/functional/rpc_misc.py` and then running the functional or fuzz tests.

ACKs for top commit:
  achow101:
    ACK fa37153288
  ryanofsky:
    Code review ACK fa37153288, just catching subprocess.CalledProcessError in test fixing up a comment since last review
  stickies-v:
    ACK fa37153288

Tree-SHA512: 2d892b838ccef6f9b25a066e7c2f6cd6f5acc94aad1d91fce62308983bd3f5c5d724897a76de4e3cc5c3678ddadc87e2ee8c87362965373526038e598dfb0101

src/test/fuzz/integer.cpp

@@ -251,9 +251,4 @@ FUZZ_TARGET(integer, .init = initialize_integer)
         } catch (const std::ios_base::failure&) {
         }
     }
-
-    try {
-        CHECK_NONFATAL(b);
-    } catch (const NonFatalCheckError&) {
-    }
 }

src/test/fuzz/rpc.cpp

@@ -381,6 +381,12 @@ FUZZ_TARGET(rpc, .init = initialize_rpc)
         arguments.push_back(ConsumeRPCArgument(fuzzed_data_provider, good_data));
     }
     try {
+        std::optional<test_only_CheckFailuresAreExceptionsNotAborts> maybe_mock{};
+        if (rpc_command == "echo") {
+            // Avoid aborting fuzzing for this specific test-only RPC with an
+            // intentional trigger_internal_bug
+            maybe_mock.emplace();
+        }
         rpc_testing_setup->CallRPC(rpc_command, arguments);
     } catch (const UniValue& json_rpc_error) {
         const std::string error_msg{json_rpc_error.find_value("message").get_str()};