fix: libduckdb-sys build fails on Windows

[maemon4095]

Fix libduckdb-sys build failure on Windows related to #268 (possibly also related to #482 and #413).

Added a line to libduckdb-sys/build.rs to specify the encoding when compiling C code.

[wyhaya]

In my testing, this PR resolves a portion of the issues.

There are still some other errors:

error: linking with `link.exe` failed: exit code: 1120
  |
  = note: "C:\\Program Files\\Microsoft Visual Studio\\2022\\Community\\VC\\Tools\\MSVC\\14.43.34808\\bin\\HostX64\\x64\\link.exe" "/NOLOGO" "C:\\Users\\dev\\AppData\\Local\\Temp\\rustcGnutTC\\symbols.o" "<11 object files omitted>" "C:\\Users\\dev\\Desktop\\duckdb-rs\\target\\debug\\deps/{liblibduckdb_sys-626df3e6a568ec49.rlib}.rlib" "<sysroot>\\lib\\rustlib\\x86_64-pc-windows-msvc\\lib/{libstd-*,libpanic_unwind-*,libwindows_targets-*,librustc_demangle-*,libstd_detect-*,libhashbrown-*,librustc_std_workspace_alloc-*,libunwind-*,libcfg_if-*,liballoc-*,librustc_std_workspace_core-*,libcore-*,libcompiler_builtins-*}.rlib" "kernel32.lib" "kernel32.lib" "advapi32.lib" "ntdll.lib" "userenv.lib" "ws2_32.lib" "dbghelp.lib" "/defaultlib:msvcrt" "/NXCOMPAT" "/LIBPATH:C:\\Users\\dev\\Desktop\\duckdb-rs\\target\\debug\\build\\libduckdb-sys-940f8639da89845a\\out" "/OUT:C:\\Users\\dev\\Desktop\\duckdb-rs\\target\\debug\\examples\\main.exe" "/OPT:REF,NOICF" "/DEBUG" "/PDBALTPATH:%_PDB%" "/NATVIS:<sysroot>\\lib\\rustlib\\etc\\intrinsic.natvis" "/NATVIS:<sysroot>\\lib\\rustlib\\etc\\liballoc.natvis" "/NATVIS:<sysroot>\\lib\\rustlib\\etc\\libcore.natvis" "/NATVIS:<sysroot>\\lib\\rustlib\\etc\\libstd.natvis"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note:    Creating library C:\Users\dev\Desktop\duckdb-rs\target\debug\examples\main.lib and object C:\Users\dev\Desktop\duckdb-rs\target\debug\examples\main.exp␍
          liblibduckdb_sys-626df3e6a568ec49.rlib(6e5d8cd65011422c-ub_src_common.o) : error LNK2019: unresolved external symbol RmStartSession referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl duckdb::AdditionalLockInfo(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >)" (?AdditionalLockInfo@duckdb@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@3@@Z)␍
          liblibduckdb_sys-626df3e6a568ec49.rlib(6e5d8cd65011422c-ub_src_common.o) : error LNK2019: unresolved external symbol RmEndSession referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl duckdb::AdditionalLockInfo(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >)" (?AdditionalLockInfo@duckdb@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@3@@Z)␍
          liblibduckdb_sys-626df3e6a568ec49.rlib(6e5d8cd65011422c-ub_src_common.o) : error LNK2019: unresolved external symbol RmRegisterResources referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl duckdb::AdditionalLockInfo(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >)" (?AdditionalLockInfo@duckdb@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@3@@Z)␍
          liblibduckdb_sys-626df3e6a568ec49.rlib(6e5d8cd65011422c-ub_src_common.o) : error LNK2019: unresolved external symbol RmGetList referenced in function "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl duckdb::AdditionalLockInfo(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >)" (?AdditionalLockInfo@duckdb@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@3@@Z)␍
          liblibduckdb_sys-626df3e6a568ec49.rlib(337470f5afaaf2c3-entropy_poll.o) : error LNK2019: unresolved external symbol BCryptGenRandom referenced in function mbedtls_platform_entropy_poll␍
          C:\Users\dev\Desktop\duckdb-rs\target\debug\examples\main.exe : fatal error LNK1120: 5 unresolved externals␍


error: could not compile `libduckdb-sys` (example "main") due to 1 previous error

This error can be fixed by the following code (from AI):

println!("cargo:rustc-link-lib=dylib=Rstrtmgr");
println!("cargo:rustc-link-lib=dylib=Bcrypt");

For me, this resolved all the errors I was encountering while building libduckdb-sys on Windows.

[maemon4095]

I found the following some lines in CMakeList.txt　https://github.com/duckdb/duckdb/blob/7c039464e452ddc3330e2691d3fa6d305521d09b/src/CMakeLists.txt#L33

These lines add Ws2_32, Rstrtmgr and Bcrypt to the link targets when using MSVC.
So I think I need to link these libraries in order to build.
However, I don't know why the build succeeds in my environment without linking these libraries.

[wyhaya]

Previously, any version of libduckdb-sys could be successfully built in GitHub Action Windows, but at some point, without changing any code, the above error started to occur. I suspect it might be related to Windows rather than DuckDB.

---

Anyway, I believe the following code can solve all build errors on Windows:

// ...
.flag_if_supported("/utf-8")

// ...
println!("cargo:rustc-link-lib=dylib=Rstrtmgr");
println!("cargo:rustc-link-lib=dylib=Bcrypt");