[config] Suppress implicit-fallthrough

Change-Id: Id36ebc2a0fa32d4e86f5a65d256ff8d59e3c17c7
diff --git a/BUILD.gn b/BUILD.gn
index 3c9c584..2efef67 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -2,9 +2,9 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/components.gni")
 import("//build/host.gni")
 import("//build/test.gni")
-import("//build/components.gni")
 import("//third_party/quickjs/compiled_js.gni")
 
 config("qjs-config") {
@@ -24,6 +24,7 @@
   # Suppress warnings in upstream code that are triggered by Fuchsia compilation flags.
   cflags = [
     "-Wno-conversion",
+    "-Wno-implicit-fallthrough",
     "-Wno-implicit-int-float-conversion",
     "-Wno-sign-compare",
     "-Wno-unused-variable",
@@ -47,7 +48,7 @@
     deps = [ "//sdk/lib/fdio" ]
   }
 
-  public_configs = [ ":qjs-config" ]
+  configs += [ ":qjs-config" ]
 }
 
 executable("qjsc") {
@@ -76,6 +77,8 @@
     ":repl",
   ]
 
+  configs += [ ":qjs-config" ]
+
   if (is_fuchsia) {
     deps += [ "//src/zircon/lib/zircon" ]
   }