Do not use umask() since it change the umask for the entire process, not just

the thread using SQLite.  Make whatever permission changes are needed using
fchmod() after the file is created, instead.

FossilOrigin-Name: 6c4c2b7dbadedac384d380efd54f12f6ccbf4ca9

test/pager1.test

@@ -883,12 +883,20 @@ do_execsql_test pager1.4.7.1 {
 tv filter {}
 db close
 tv delete 
+catch {
+  test_syscall install fchmod
+  test_syscall fault 1 1
+}
 do_test pager1.4.7.2 {
   faultsim_restore_and_reopen
   catch {file attributes test.db-journal -permissions r--------}
   catch {file attributes test.db-journal -readonly 1}
   catchsql { SELECT * FROM t1 }
 } {1 {unable to open database file}}
+catch {
+  test_syscall reset
+  test_syscall fault 0 0
+}
 do_test pager1.4.7.3 {
   db close
   catch {file attributes test.db-journal -permissions rw-rw-rw-}