clang: Suppress a new warning in sqlite.

third_party/sqlite/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("sqlite_config") {
   include_dirs = [ "." ]
 }
 
 source_set("sqlite") {
   sources = [
@@ skipping 65 matching lines @@
       "DSQLITE_DEFAULT_FILE_FORMAT=4",
     ]
   }
 
   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 = [
     "//third_party/icu",
   ]
 }
 
@@ skipping 12 matching lines @@
     ]
   }
 }
 
 if (is_ios) {
   source_set("sqlite_regexp") {
     sources = [ "src/ext/icu/icu.c" ]
     deps = [ "//third_party/icu" ]
   }
 }