[arm64] Add missing allow_macro_instructions() check.

Change-Id: I21f88bffb9fcc08c5b4616d77f90565714124082
Reviewed-on: https://chromium-review.googlesource.com/1076607Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#53486}

src/arm64/macro-assembler-arm64-inl.h

@@ -286,6 +286,7 @@ void TurboAssembler::Asr(const Register& rd, const Register& rn,
 }
 
 void TurboAssembler::B(Label* label) {
+  DCHECK(allow_macro_instructions());
   b(label);
   CheckVeneerPool(false, false);
 }