[config] Suppress implicit fallthrough

Change-Id: I7bb9837b37d1b254225cc91dca3587c8bd8fb3ed
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/Vulkan-Tools/+/527264
Reviewed-by: Shai Barack <shayba@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index ec111f4..e27d306 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -92,8 +92,12 @@
     args += [ raw_vulkan_data_dir ] + rebase_path(sources, root_build_dir)
   }
 
-  config("Wno-missing-field-initializers") {
-    cflags = [ "-Wno-missing-field-initializers" ]
+  config("vulkaninfo_warnings") {
+    cflags = [
+      "-Wno-conversion",
+      "-Wno-implicit-fallthrough",
+      "-Wno-missing-field-initializers",
+    ]
   }
 
   executable("vulkaninfo") {
@@ -109,10 +113,7 @@
       "//third_party/Vulkan-Loader:libvulkan",
     ]
 
-    configs += [
-      "//build/config:Wno-conversion",
-      ":Wno-missing-field-initializers",
-    ]
+    configs += [ ":vulkaninfo_warnings" ]
     configs -= [ "//build/config:no_exceptions" ]
 
     # TODO(fxbug.dev/51937): Remove once exceptions work with shadow call stack.