Define MAP_FAILED if not already defined

[markusalbertgraf]

#715 Add missing constant MAP_FAILED for Windows.
Can't test this, as I have not Windows. Just copied what others on github do.

[markusalbertgraf]

Fixes #719 and is the solution of @bjornblissing

[anaslimem]

I will try it now and tell you if it works thank you :)

[anaslimem]

i think i need to wait for you for the next release!

[obfuscate]

Hello there. Any chance to merge it? because right now it ruins compilation of tracy from vcpkg on windows:

build\windows-msvc-msbuild\vcpkg_installed\x64-windows\include\usearch/index_plugins.hpp(962): error C3861: 'MAP_FAILED': identifier not found
build\windows-msvc-msbuild\vcpkg_installed\x64-windows\include\usearch/index_plugins.hpp(962): note: the template instantiation context (the oldest one first) is
build\windows-msvc-msbuild\vcpkg_installed\x64-windows\include\usearch/index_plugins.hpp(878): note: while compiling class template 'unum::usearch::memory_mapping_allocator_gt'
build\windows-msvc-msbuild\vcpkg_installed\x64-windows\include\usearch/index_plugins.hpp(962): error C2065: 'MAP_FAILED': undeclared identifier

[ashvardanian]

Gotcha, @obfuscate! I'll merge it in a 3-4 hours. Sorry it's taking a while, I'm trying to push the ashvardanian/SimSIMD#220 release through the line to merge it into USearch, but it seems like this patch is quite urgent 🤔