test: Add missing shift-base:nanobench.h suppression

Otherwise it is not possible to run bench_bitcoin with clang-12 + ASAN
compiled.

Output:

$ src/bench/bench_bitcoin
bench/nanobench.h:1107:15: runtime error: left shift of 4982565676696827473 by 27 places cannot be represented in type 'uint64_t' (aka 'unsigned long')
    #0 0x5623d6a13137 in ankerl::nanobench::Rng::rotl(unsigned long, unsigned int) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:1107:15
    #1 0x5623d6a13137 in ankerl::nanobench::Rng::operator()() /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:1075:10
    #2 0x5623d6a05c5b in ankerl::nanobench::Rng::Rng(unsigned long) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:3135:9
    #3 0x5623d6a0ca51 in ankerl::nanobench::detail::IterationLogic::Impl::Impl(ankerl::nanobench::Bench const&) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:2206:13
    #4 0x5623d69f8f73 in ankerl::nanobench::detail::IterationLogic::IterationLogic(ankerl::nanobench::Bench const&) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:2215:18
    #5 0x5623d690f165 in ankerl::nanobench::Bench& ankerl::nanobench::Bench::run<AddrManAdd(ankerl::nanobench::Bench&)::$_0>(AddrManAdd(ankerl::nanobench::Bench&)::$_0&&) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/./bench/nanobench.h:1114:28
    #6 0x5623d690e26e in AddrManAdd(ankerl::nanobench::Bench&) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/bench/addrman.cpp:76:11
    #7 0x5623d69279d6 in void std::__invoke_impl<void, void (*&)(ankerl::nanobench::Bench&), ankerl::nanobench::Bench&>(std::__invoke_other, void (*&)(ankerl::nanobench::Bench&), ankerl::nanobench::Bench&) /usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/invoke.h:60:14
    #8 0x5623d6927921 in std::enable_if<is_invocable_r_v<void, void (*&)(ankerl::nanobench::Bench&), ankerl::nanobench::Bench&>, void>::type std::__invoke_r<void, void (*&)(ankerl::nanobench::Bench&), ankerl::nanobench::Bench&>(void (*&)(ankerl::nanobench::Bench&), ankerl::nanobench::Bench&) /usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/invoke.h:110:2
    #9 0x5623d692775f in std::_Function_handler<void (ankerl::nanobench::Bench&), void (*)(ankerl::nanobench::Bench&)>::_M_invoke(std::_Any_data const&, ankerl::nanobench::Bench&) /usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/std_function.h:291:9
    bitcoin#10 0x5623d692dbd5 in std::function<void (ankerl::nanobench::Bench&)>::operator()(ankerl::nanobench::Bench&) const /usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/std_function.h:622:14
    bitcoin#11 0x5623d692cd44 in benchmark::BenchRunner::RunAll(benchmark::Args const&) /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/bench/bench.cpp:65:13
    bitcoin#12 0x5623d69282bf in main /bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/bench/bench_bitcoin.cpp:63:5
    bitcoin#13 0x7f6812010564 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x28564)
    bitcoin#14 0x5623d685f4dd in _start (/bitcoin/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/src/bench/bench_bitcoin+0x13754dd)

SUMMARY: UndefinedBehaviorSanitizer: invalid-shift-base bench/nanobench.h:1107:15 in

$ clang --version
Ubuntu clang version 12.0.0-1ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

test/sanitizer_suppressions/ubsan

@@ -96,6 +96,7 @@ implicit-unsigned-integer-truncation:crypto/
 implicit-unsigned-integer-truncation:leveldb/
 # std::variant warning fixed in https://github.com/gcc-mirror/gcc/commit/074436cf8cdd2a9ce75cadd36deb8301f00e55b9
 implicit-unsigned-integer-truncation:std::__detail::__variant::_Variant_storage
+shift-base:nanobench.h
 shift-base:*/include/c++/
 shift-base:arith_uint256.cpp
 shift-base:crypto/