Add epoll and do more release readiness changes

This change also pays off some of the remaining technical debt with
stdio, file descriptors, and memory managemnt polyfills.

libc/calls/hefty/copyfile.c

@@ -55,7 +55,7 @@ static textwindows int copyfile$nt(const char *src, const char *dst,
     }
     return 0;
   } else {
-    return winerr();
+    return __winerr();
   }
 }
 

libc/calls/hefty/dirstream.c

@@ -74,7 +74,7 @@ static textwindows noinline DIR *opendir$nt(const char *name) {
   if ((res->fd = FindFirstFile(name16, &res->windata)) != -1) {
     return res;
   } else {
-    winerr();
+    __winerr();
     free(res);
     return NULL;
   }
@@ -220,7 +220,7 @@ int closedir(DIR *dir) {
     if (!IsWindows()) {
       rc = close(dir->fd);
     } else {
-      rc = FindClose(dir->fd) ? 0 : winerr();
+      rc = FindClose(dir->fd) ? 0 : __winerr();
     }
     free(dir);
   } else {

libc/calls/hefty/fork-nt.c

@@ -67,7 +67,7 @@ textwindows void WinMainForked(void) {
   char16_t *p;
   uint64_t size;
   char16_t var[21 + 1 + 21 + 1];
-  uint32_t i, varlen, protect, access;
+  uint32_t i, varlen, protect, access, oldprot;
   varlen = GetEnvironmentVariable(u"_FORK", var, ARRAYLEN(var));
   if (!varlen || varlen >= ARRAYLEN(var)) return;
   p = var;
@@ -98,11 +98,13 @@ textwindows void WinMainForked(void) {
         break;
     }
     if (_mmi.p[i].flags & MAP_PRIVATE) {
-      MapViewOfFileExNuma(
-          (_mmi.p[i].h = CreateFileMappingNuma(-1, NULL, protect, 0, size, NULL,
-                                               kNtNumaNoPreferredNode)),
-          access, 0, 0, size, addr, kNtNumaNoPreferredNode);
+      MapViewOfFileExNuma((_mmi.p[i].h = CreateFileMappingNuma(
+                               -1, NULL, kNtPageExecuteReadwrite, 0, size, NULL,
+                               kNtNumaNoPreferredNode)),
+                          kNtFileMapRead | kNtFileMapWrite | kNtFileMapExecute,
+                          0, 0, size, addr, kNtNumaNoPreferredNode);
       ReadAll(h, addr, size);
+      VirtualProtect(addr, size, protect, &oldprot);
     } else {
       MapViewOfFileExNuma(_mmi.p[i].h, access, 0, 0, size, addr,
                           kNtNumaNoPreferredNode);
@@ -148,7 +150,7 @@ textwindows int fork$nt(void) {
       }
       unsetenv("_FORK");
     } else {
-      rc = winerr();
+      rc = __winerr();
     }
   } else {
     rc = 0;

libc/calls/hefty/ntspawn.c

@@ -78,7 +78,7 @@ textwindows int ntspawn(
                       opt_out_lpProcessInformation)) {
       rc = 0;
     } else {
-      rc = winerr();
+      rc = __winerr();
     }
   } else {
     rc = -1;

libc/calls/hefty/spawnve-nt.c

@@ -49,14 +49,14 @@ textwindows int spawnve$nt(unsigned flags, int stdiofds[3], const char *program,
   sti.cb = sizeof(sti);
   sti.dwFlags = kNtStartfUsestdhandles;
 
-  if ((pid = createfd()) == -1) return -1;
+  if ((pid = __getemptyfd()) == -1) return -1;
 
   for (i = 0; i < 3; ++i) {
     if (stdiofds[i] == -1) {
       x = &h;
       y = &sti.stdiofds[i];
       if (kIoMotion[i]) xchg(&x, &y);
-      if ((tubes[i] = createfd()) != -1 &&
+      if ((tubes[i] = __getemptyfd()) != -1 &&
           CreatePipe(x, y, &kNtIsInheritable, 0)) {
         g_fds.p[tubes[i]].handle = h;
       } else {

libc/calls/hefty/ttyname_r.c

@@ -76,7 +76,7 @@ int ttyname_r(int fd, char *buf, size_t size) {
   } else if (IsFreebsd()) {
     return ttyname$freebsd(fd, buf, size);
   } else if (IsWindows()) {
-    if (isfdkind(fd, kFdFile)) {
+    if (__isfdkind(fd, kFdFile)) {
       return ttyname$nt(fd, buf, size);
     } else {
       return ebadf();