Fix optional neon support

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 456ab1958edeedcf6dd59b21420da7d2f46f8b31..09f8e6270904dfcf32a5ca15d05c00a8e1ae916c 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -134,7 +134,6 @@ config("compiler") {
       if (!is_android_webview_build) {
         cflags += [
           "-march=$arm_arch",
-          "-mfpu=$arm_fpu",
           "-mfloat-abi=$arm_float_abi",
         ]
         if (arm_tune != "") {
@@ -314,6 +313,14 @@ config("compiler") {
   }
 }
 
+config("compiler_arm_fpu") {
+  if (cpu_arch == "arm" && !is_android_webview_build) {
+    cflags = [
+      "-mfpu=$arm_fpu",
+    ]
+  }
+}
+
 # runtime_library -------------------------------------------------------------
 #
 # Sets the runtime library and associated options.