Merge bitcoin#21586: test: Add missing suppression for signed-integer…

…-overflow:txmempool.cpp

fad8a97 test: Add missing suppression for signed-integer-overflow:txmempool.cpp (MarcoFalke)

Pull request description:

  Otherwise the fuzzer will crash:

  ```
  txmempool.cpp:847:15: runtime error: signed integer overflow: 8138645194045128704 + 4611686018427387904 cannot be represented in type 'long'
      #0 0x558ff1838d4c in CTxMemPool::PrioritiseTransaction(uint256 const&, long const&) /root/fuzz_dir/scratch/fuzz_gen/code/src/txmempool.cpp:847:15
      #1 0x558ff196e723 in LoadMempool(CTxMemPool&, CChainState&, std::function<_IO_FILE* (boost::filesystem::path const&, char const*)>) /root/fuzz_dir/scratch/fuzz_gen/code/src/validation.cpp:5053:22
      #2 0x558ff13f37ab in validation_load_mempool_fuzz_target(Span<unsigned char const>) /root/fuzz_dir/scratch/fuzz_gen/code/src/test/fuzz/validation_load_mempool.cpp:32:11
      #3 0x558ff1083378 in std::_Function_handler<void (Span<unsigned char const>), void (*)(Span<unsigned char const>)>::_M_invoke(std::_Any_data const&, Span<unsigned char const>&&) /usr/bin/../lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/std_function.h:300:2
      #4 0x558ff22a749d in std::function<void (Span<unsigned char const>)>::operator()(Span<unsigned char const>) const /usr/bin/../lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/std_function.h:688:14
      #5 0x558ff22a70e8 in LLVMFuzzerTestOneInput /root/fuzz_dir/scratch/fuzz_gen/code/src/test/fuzz/fuzz.cpp:63:5
      #6 0x558ff0f83543 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) fuzzer.o
      #7 0x558ff0f6d442 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) fuzzer.o
      #8 0x558ff0f7323a in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) fuzzer.o
      bitcoin#9 0x558ff0f9ef82 in main (/root/fuzz_dir/scratch/fuzz_gen/code/src/test/fuzz/fuzz+0x196df82)
      bitcoin#10 0x7f1237f310b2 in __libc_start_main /build/glibc-eX1tMB/glibc-2.31/csu/../csu/libc-start.c:308:16
      bitcoin#11 0x558ff0f4816d in _start (/root/fuzz_dir/scratch/fuzz_gen/code/src/test/fuzz/fuzz+0x191716d)

Top commit has no ACKs.

Tree-SHA512: 94c13771054b4acfb83e3dcfa09beb3f9d0ca0e025d3993cdf2e46df6456f227565b31fd4377b8dd86c567aeee800f293ac57a470c6f5f81e9177d460e7bd705

test/sanitizer_suppressions/ubsan

@@ -100,3 +100,4 @@ shift-base:leveldb/
 shift-base:net_processing.cpp
 shift-base:streams.h
 shift-base:util/bip32.cpp
+signed-integer-overflow:txmempool.cpp