When compiling without external signer support, the resulted `bench_bitcoin.exe` fails on Windows:
```
>.\bench_bitcoin.exe -filter=AddrManSelectByNetwork
Error: bad optional access
```

Steps to reproduce the failure:
- cross compiling on Ubuntu 22.04:
```
$ make -j $(nproc) -C depends HOST=x86_64-w64-mingw32 NO_QT=1
$ ./autogen.sh
$ ./configure CONFIG_SITE=$PWD/depends/x86_64-w64-mingw32/share/config.site --disable-external-signer
$ make -j $(nproc)
```
- compiling natively on Windows:

Apply the diff as follows:
```diff
--- a/build_msvc/bitcoin_config.h.in
+++ b/build_msvc/bitcoin_config.h.in
@@ -41,9 +41,6 @@
 /* Define this symbol to enable ZMQ functions */
 #define ENABLE_ZMQ 1
 
-/* define if external signer support is enabled (requires Boost::Process) */
-#define ENABLE_EXTERNAL_SIGNER /**/
-
 /* Define to 1 if you have the declaration of `be16toh', and to 0 if you
    don't. */
 #define HAVE_DECL_BE16TOH 0
```
Then
```
>py -3 build_msvc\msvc-autogen.py
>msbuild build_msvc\bitcoin.sln -property:Configuration=Release -verbosity:minimal
>src\bench_bitcoin.exe -filter=AddrManSelectByNetwork
Error: bad optional access
```

---

The failure does not manifest itself when running `bench_bitcoin.exe` using Wine on Linux.
BOOST_CHECK(!ParseFixedPoint("10000000000.00000001", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("-10000000000.00000009", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("10000000000.00000009", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("-99999999999.99999999", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("99999909999.09999999", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("92233720368.54775807", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("92233720368.54775808", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("-92233720368.54775808", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("-92233720368.54775809", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("1.1e", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("1.1e-", 8, &amount));
    BOOST_CHECK(!ParseFixedPoint("1.", 8, &amount));
    
    BOOST_CHECK(ParseFixedPoint("0.001", 3, &amount));
    BOOST_CHECK_EQUAL(amount, CAmount{1});
    BOOST_CHECK(!ParseFixedPoint("0.0009", 3, &amount));
    BOOST_CHECK(!ParseFixedPoint("31.00100001", 3, &amount));
    BOOST_CHECK(!ParseFixedPoint("31.0011", 3, &amount));
    BOOST_CHECK(!ParseFixedPoint("31.99999999", 3, &amount));
    BOOST_CHECK(!ParseFixedPoint("31.999999999999999999999", 3, &amount));
}
static void TestOtherThread(fs::path dirname, fs::path lockname, bool *result)
{
    *result = LockDirectory(dirname, lockname);
}
#ifndef WIN32 
static constexpr char LockCommand = 'L';
static constexpr char UnlockCommand = 'U';
static constexpr char ExitCommand = 'X';
[[noreturn]] static void TestOtherProcess(fs::path dirname, fs::path lockname, int fd)