std.os.windows additions and fixes

Author: Szwagi

lib/std/os/windows.zig

@@ -2631,6 +2631,7 @@ pub const HWND = *opaque {};
 pub const HDC = *opaque {};
 pub const HGLRC = *opaque {};
 pub const FARPROC = *opaque {};
+pub const PROC = *opaque {};
 pub const INT = c_int;
 pub const LPCSTR = [*:0]const CHAR;
 pub const LPCVOID = *const anyopaque;
@@ -3433,6 +3434,10 @@ pub const E_HANDLE = @as(c_long, @bitCast(@as(c_ulong, 0x80070006)));
 pub const E_OUTOFMEMORY = @as(c_long, @bitCast(@as(c_ulong, 0x8007000E)));
 pub const E_INVALIDARG = @as(c_long, @bitCast(@as(c_ulong, 0x80070057)));
 
+pub fn HRESULT_CODE(hr: HRESULT) Win32Error {
+    return @enumFromInt(hr & 0xFFFF);
+}
+
 pub const FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;
 pub const FILE_FLAG_DELETE_ON_CLOSE = 0x04000000;
 pub const FILE_FLAG_NO_BUFFERING = 0x20000000;

lib/std/os/windows/kernel32.zig

@@ -193,7 +193,7 @@ pub extern "kernel32" fn GetExitCodeProcess(hProcess: HANDLE, lpExitCode: *DWORD
 
 pub extern "kernel32" fn GetFileSizeEx(hFile: HANDLE, lpFileSize: *LARGE_INTEGER) callconv(WINAPI) BOOL;
 
-pub extern "kernel32" fn GetFileAttributesW(lpFileName: [*]const WCHAR) callconv(WINAPI) DWORD;
+pub extern "kernel32" fn GetFileAttributesW(lpFileName: [*:0]const WCHAR) callconv(WINAPI) DWORD;
 
 pub extern "kernel32" fn GetModuleFileNameW(hModule: ?HMODULE, lpFilename: [*]u16, nSize: DWORD) callconv(WINAPI) DWORD;
 
@@ -392,7 +392,7 @@ pub extern "kernel32" fn WriteFileEx(
 
 pub extern "kernel32" fn LoadLibraryW(lpLibFileName: [*:0]const u16) callconv(WINAPI) ?HMODULE;
 
-pub extern "kernel32" fn GetProcAddress(hModule: HMODULE, lpProcName: [*]const u8) callconv(WINAPI) ?FARPROC;
+pub extern "kernel32" fn GetProcAddress(hModule: HMODULE, lpProcName: [*:0]const u8) callconv(WINAPI) ?FARPROC;
 
 pub extern "kernel32" fn FreeLibrary(hModule: HMODULE) callconv(WINAPI) BOOL;