We should never allocate a 0-sized buffer, so never grow from 0.

src/arm64/assembler-arm64.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
@@ skipping 2753 matching lines @@
 
   return true;
 }
 
 
 void Assembler::GrowBuffer() {
   if (!own_buffer_) FATAL("external code buffer is too small");
 
   // Compute new buffer size.
   CodeDesc desc;  // the new buffer
-  if (buffer_size_ == 0) {
-    desc.buffer_size = kMinimalBufferSize;
-  } else if (buffer_size_ < 1 * MB) {
+  if (buffer_size_ < 1 * MB) {
     desc.buffer_size = 2 * buffer_size_;
   } else {
     desc.buffer_size = buffer_size_ + 1 * MB;
   }
   CHECK_GT(desc.buffer_size, 0);  // No overflow.
 
   byte* buffer = reinterpret_cast<byte*>(buffer_);
 
   // Set up new buffer.
   desc.buffer = NewArray<byte>(desc.buffer_size);
@@ skipping 329 matching lines @@
   movz(scratch, (target_offset >> 16) & 0xFFFF, 16);
   movk(scratch, (target_offset >> 32) & 0xFFFF, 32);
   DCHECK((target_offset >> 48) == 0);
   add(rd, rd, scratch);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64