A64: Make branch to deferred code in StringCharFromCode longer.

src/a64/codegen-a64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 461 matching lines @@
   // Handle external strings.
   __ Bind(&external_string);
   if (FLAG_debug_code) {
     // Assert that we do not have a cons or slice (indirect strings) here.
     // Sequential strings have already been ruled out.
     __ Tst(result, kIsIndirectStringMask);
     __ Assert(eq, "external string expected, but not found");
   }
   // 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;
   __ Bind(&check_encoding);
   STATIC_ASSERT(kTwoByteStringTag == 0);
   __ TestAndBranchIfAnySet(result, kStringEncodingMask, &ascii);
   // Two-byte string.
   __ Ldrh(result, MemOperand(string, index, LSL, 1));
   __ B(&done);
   __ Bind(&ascii);
@@ skipping 122 matching lines @@
   __ Fmul(result, double_temp3, double_temp1);
 
   __ Bind(&done);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_A64