Warning on cast from `farproc_t` in Clang 19.1 for Windows

[joaquintides]

This problem arises on Boost.Unordered tests with Clang 19.1 for Visual Studio 2022 v17.13.3 (clang-cl). Full logs here.

2025-03-12T16:47:36.5368174Z .\boost/interprocess/detail/win32_api.hpp(1122,59): error: cast from 'farproc_t' (aka 'int (*)() __attribute__((stdcall))') to 'NtQuerySystemInformation_t' (aka 'long (*)(int, void *, unsigned long, unsigned long *) __attribute__((stdcall))') converts to incompatible function type [-Werror,-Wcast-function-type-mismatch]
2025-03-12T16:47:36.5371616Z  1122 |    NtQuerySystemInformation_t pNtQuerySystemInformation = reinterpret_cast<NtQuerySystemInformation_t>
2025-03-12T16:47:36.5373049Z       |                                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2025-03-12T16:47:36.5373933Z  1123 |          (dll_func::get(dll_func::NtQuerySystemInformation));

(Same error happens at lines 1122, 1546, 1559, 1570, 1329, 1331, 1403, 1404, 1329 of boost/interprocess/detail/win32_api.hpp. ) This seems to be connected to this issue: if this is the case, an intermediate cast tp void * should suffice to silent the warning.

[igaztanaga]

Let's see if this fixes most occurrences of the problem, instead of that single one...

[pdimov]

I brought this up in llvm/llvm-project#86131 and we'll hopefully see that fixed on the Clang side in llvm/llvm-project#135660.