Windows: Rework kernel32 apis

To facilitate ziglang#1840, this commit slims `std.windows.kernel32` to only
have the functions needed by the standard library. Since this will break
projects that relied on these, I offer two solutions:

- Make an argument as to why certain functions should be added back in.
  Note that they may just be wrappers around `ntdll` APIs, which would
  go against ziglang#1840.
  If necessary I'll add them back in *and* make wrappers in
  `std.windows` for it.
- Maintain your own list of APIs. This is the option taken by bun[1],
  where they wrap functions with tracing.
- Use `zigwin32`.

I've also added TODO comments that specify which functions can be
reimplemented using `ntdll` APIs in the future.

Other changes:
- Group functions into groups (I/O, process management etc.).
- Synchronize definitions against Microsoft documentation to use the
  proper parameter types/names.
- Break all functions with parameters over multiple lines.

lib/std/debug.zig

@@ -1925,7 +1925,7 @@ pub const DebugInfo = struct {
                     @memcpy(name_buffer[0..4], &[_]u16{ '\\', '?', '?', '\\' });
 
                     const process_handle = windows.kernel32.GetCurrentProcess();
-                    const len = windows.kernel32.K32GetModuleFileNameExW(
+                    const len = windows.kernel32.GetModuleFileNameExW(
                         process_handle,
                         module.handle,
                         @ptrCast(&name_buffer[4]),

lib/std/os/windows.zig

@@ -725,8 +725,8 @@ pub const GetCurrentDirectoryError = error{
 /// The result is a slice of `buffer`, indexed from 0.
 /// The result is encoded as [WTF-8](https://simonsapin.github.io/wtf-8/).
 pub fn GetCurrentDirectory(buffer: []u8) GetCurrentDirectoryError![]u8 {
-    var wtf16le_buf: [PATH_MAX_WIDE]u16 = undefined;
-    const result = kernel32.GetCurrentDirectoryW(wtf16le_buf.len, &wtf16le_buf);
+    var wtf16le_buf: [PATH_MAX_WIDE:0]u16 = undefined;
+    const result = kernel32.GetCurrentDirectoryW(wtf16le_buf.len + 1, &wtf16le_buf);
     if (result == 0) {
         switch (kernel32.GetLastError()) {
             else => |err| return unexpectedError(err),
@@ -2764,7 +2764,7 @@ pub fn loadWinsockExtensionFunction(comptime T: type, sock: ws2_32.SOCKET, guid:
 pub fn unexpectedError(err: Win32Error) UnexpectedError {
     if (std.posix.unexpected_error_tracing) {
         // 614 is the length of the longest windows error description
-        var buf_wstr: [614]WCHAR = undefined;
+        var buf_wstr: [614:0]WCHAR = undefined;
         const len = kernel32.FormatMessageW(
             FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
             null,