Improve system call support on NT

- Improve i/o perf on New Technology
- Code cleanup on read() for New Technology
- Fix bad bug with dup() of socket on New Technology
- Clean up some more strace errors on New Technology

libc/intrin/getfileattributes.greg.c

@@ -0,0 +1,41 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/internal.h"
+#include "libc/calls/strace.internal.h"
+#include "libc/intrin/describeflags.internal.h"
+#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/nt/files.h"
+#include "libc/nt/thunk/msabi.h"
+
+extern typeof(GetFileAttributes) *const __imp_GetFileAttributesW __msabi;
+
+/**
+ * Gets file info on the New Technology.
+ *
+ * @return handle, or -1 on failure
+ * @note this wrapper takes care of ABI, STRACE(), and __winerr()
+ */
+textwindows uint32_t GetFileAttributes(const char16_t *lpPathName) {
+  uint32_t flags;
+  flags = __imp_GetFileAttributesW(lpPathName);
+  if (flags == -1u) __winerr();
+  STRACE("GetFileAttributes(%#hs) → %s% m", lpPathName,
+         DescribeNtFileFlagsAndAttributes(flags));
+  return flags;
+}