[sql] Enable disabled clang warnings.

third_party/sqlite/BUILD.gn

Index: third_party/sqlite/BUILD.gn
diff --git a/third_party/sqlite/BUILD.gn b/third_party/sqlite/BUILD.gn
index 5e3c8c566ff4832f7b13562d5289303a05d90eb5..6f301ca7167145ba6daa1bab4b76936f024f6497 100644
--- a/third_party/sqlite/BUILD.gn
+++ b/third_party/sqlite/BUILD.gn
@@ -88,20 +88,6 @@ source_set("sqlite") {
     ]
   }
 
-  if (is_clang) {
-    cflags += [
-      # sqlite does `if (*a++ && *b++);` in a non-buggy way.
-      "-Wno-empty-body",
-
-      # sqlite has some `unsigned < 0` checks.
-      "-Wno-tautological-compare",
-
-      # Needed because we don't have this commit yet:
-      # https://github.com/mackyle/sqlite/commit/25df0fa050dcc9be7fb937b8e25be24049b3fef0
-      "-Wno-pointer-bool-conversion",
-    ]
-  }
-
   public_configs = [ ":sqlite_config" ]
 
   deps = [