Backport more SQLite changes to enable system-sqlite experiments.

third_party/sqlite/src/test/syscall.test

Index: third_party/sqlite/src/test/syscall.test
diff --git a/third_party/sqlite/src/test/syscall.test b/third_party/sqlite/src/test/syscall.test
index 4442612ab0df9c287a8cb114fdf8902f5f185e65..201bd63647bba7d29e799fde6325dee26ad45131 100644
--- a/third_party/sqlite/src/test/syscall.test
+++ b/third_party/sqlite/src/test/syscall.test
@@ -59,7 +59,7 @@ do_test 2.1.2 { test_syscall exists nosuchcall } 0
 foreach s {
     open close access getcwd stat fstat ftruncate
     fcntl read pread write pwrite fchmod fallocate
-    pread64 pwrite64
+    pread64 pwrite64 unlink openDirectory
 } {
   if {[test_syscall exists $s]} {lappend syscall_list $s}
 }