[jumbo] arm unittests fixup

Avoid F5 symbol clash.

Bug: chromium:770684
Change-Id: I9e851c1fe5abbdc4d032b7efdd0462c96d0c8ef3
Reviewed-on: https://chromium-review.googlesource.com/696063Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Mostyn Bramley-Moore <mostynb@vewd.com>
Cr-Commit-Position: refs/heads/master@{#48267}

test/cctest/test-assembler-arm.cc

@@ -40,6 +40,7 @@
 
 namespace v8 {
 namespace internal {
+namespace test_assembler_arm {
 
 using base::RandomNumberGenerator;
 
@@ -3994,5 +3995,6 @@ TEST(use_scratch_register_scope) {
 
 #undef __
 
+}  // namespace test_assembler_arm
 }  // namespace internal
 }  // namespace v8

test/cctest/test-macro-assembler-arm.cc

@@ -36,6 +36,7 @@
 
 namespace v8 {
 namespace internal {
+namespace test_macro_assembler_arm {
 
 typedef void* (*F)(int x, int y, int p2, int p3, int p4);
 
@@ -406,5 +407,6 @@ TEST(ReplaceLane) {
 
 #undef __
 
+}  // namespace test_macro_assembler_arm
 }  // namespace internal
 }  // namespace v8