pass O_CLOEXEC in ios_file. closes JuliaLang#11399

Author: JeffBezanson

src/support/ios.c

@@ -853,9 +853,9 @@ ios_t *ios_file(ios_t *s, const char *fname, int rd, int wr, int create, int tru
     if (!wlen) goto open_file_err;
     wchar_t *fname_w = (wchar_t*)alloca(wlen*sizeof(wchar_t));
     if (!MultiByteToWideChar(CP_UTF8, 0, fname, -1, fname_w, wlen)) goto open_file_err;
-    fd = _wopen(fname_w, flags | O_BINARY, _S_IREAD | _S_IWRITE);
+    fd = _wopen(fname_w, flags | O_BINARY | O_NOINHERIT, _S_IREAD | _S_IWRITE);
 #else
-    fd = open(fname, flags, S_IRUSR | S_IWUSR /* 0600 */ | S_IRGRP | S_IROTH /* 0644 */);
+    fd = open(fname, flags | O_CLOEXEC, S_IRUSR | S_IWUSR /* 0600 */ | S_IRGRP | S_IROTH /* 0644 */);
 #endif
     s = ios_fd(s, fd, 1, 1);
     if (fd == -1)