A64: Make branch to deferred code in StringCharFromCode longer.

src/a64/codegen-a64.cc

Index: src/a64/codegen-a64.cc
diff --git a/src/a64/codegen-a64.cc b/src/a64/codegen-a64.cc
index 924c271b3024fd8c197082cd53237a779f70bc66..27d2a431182721c013880b805d59e2eb0cae8b37 100644
--- a/src/a64/codegen-a64.cc
+++ b/src/a64/codegen-a64.cc
@@ -479,7 +479,10 @@ void StringCharLoadGenerator::Generate(MacroAssembler* masm,
   }
   // Rule out short external strings.
   STATIC_CHECK(kShortExternalStringTag != 0);
-  __ TestAndBranchIfAnySet(result, kShortExternalStringMask, call_runtime);
+  // TestAndBranchIfAnySet can emit Tbnz. Do not use it because call_runtime
+  // can be bound far away in deferred code.
+  __ Tst(result, kShortExternalStringMask);
+  __ B(ne, call_runtime);
   __ Ldr(string, FieldMemOperand(string, ExternalString::kResourceDataOffset));
 
   Label ascii, done;