builder: fix non-ASCII pathname under Windows

[kbkpbot]

This PR may help solve #20743, #21502, #21718

Because Windows use CP_ACP encoding, not UTF-8. So the generated rsp file should be encoded in CP_ACP/ANSI encoding under Windows.

This PR will help users build non-ASCII filename/pathname:

D:\测试目录\你好.v

你好.exe

[spytheman]

Importing encoding.iconv in the compiler is not a good idea.
It will make a module, that depends on the presence of a thirdparty library, that we do not ship with V, a dependency for bootstrapping the compiler.

Besides, the V compiler already has no problem with non ASCII pathnames under windows or anything else.

What does have problem with those, on windows, is the prebuilt tcc executable that we ship in vlang/tccbin .

You can verify that by just using -cc gcc or -cc msvc when building a V program, placed in a path, that has non ASCII characters in it.

[spytheman]

As for:

Because Windows use CP_ACP encoding, not UTF-8. So the generated rsp file should be encoded in CP_ACP/ANSI encoding under Windows.

That is worth doing in a private function in v.builder, that has a $if windows { branch, containing just a stripped down version of the code needed for converting utf8 to CP_ACP, not the entire encoding.iconv module (that also has a lot of unrelated stuff in it, that can break bootstrapping on not just windows).

[spytheman]

It is interesting though if only the encoding of the .rsp file has to change 🤔 .
Does passing -no-rsp fix building with tcc on windows?

[spytheman]

On windows-11 this works, both with and without -no-rsp 🤔 :

[spytheman]

The 你好.v file also works:

[kbkpbot]

This is not good for me. As tcc not work with non-ASCII filename.
Windows 10

V full version: V 0.4.8 0390c07
OS: windows, Microsoft Windows 10 ҵ LTSC v19044 64 λ
Processor: 16 cpus, 64bit, little endian,

getwd: D:\v\v\v
vexe: D:\v\v\v\v.exe
vexe mtime: 2024-10-04 11:45:39

vroot: OK, value: D:\v\v\v
VMODULES: OK, value: C:\Users\DDT.vmodules
VTMP: OK, value: C:\Users\DDT\AppData\Local\Temp\v_0

Git version: git version 2.43.0.windows.1
Git vroot status: 0.4.8-37-g0390c070-dirty
.git/config present: true

CC version: Error: 'cc' is not recognized as an internal or external command,
operable program or batch file.

thirdparty/tcc status: thirdparty-windows-amd64 b425ac82