message: sbrk fix for new wavm implementation
  When wavm interface was refactored sbrk initialization was placed in the wrong spot. Due to shared memory, sbrk init needs to go after resetMemory() call
diff: @@ -103,7 +103,6 @@ void entry::reset(const info& base_info) {
  if(default_mem) {
  shrinkMemory(default_mem, getMemoryNumPages(default_mem) - 1);
  }
  - sbrk_bytes = base_info.default_sbrk_bytes;
  }
  void entry::prepare( const info& base_info ) {
  @@ -114,6 +113,7 @@ void entry::prepare( const info& base_info ) {
  char* memstart = &memoryRef<char>(getDefaultMemory(instance), 0);
  memcpy(memstart, base_info.mem_image.data(), base_info.mem_image.size());
  + sbrk_bytes = Runtime::getMemoryNumPages(memory_instance) << IR::numBytesPerPageLog2;
  }
  }
  @@ -128,14 +128,7 @@ entry entry::build(const char* wasm_binary, size_t wasm_binary_size) {
  ModuleInstance *instance = instantiateModule(*module, std::move(link_result.resolvedImports));
  FC_ASSERT(instance != nullptr);
  - MemoryInstance* current_memory = Runtime::getDefaultMemory(instance);
  -
  - uint32_t sbrk_bytes = 0;
  - if(current_memory) {
  - sbrk_bytes = Runtime::getMemoryNumPages(current_memory) << IR::numBytesPerPageLog2;
  - }
  -
  - return entry(instance, module, sbrk_bytes);
  + return entry(instance, module, 0);
  };
  info::info( const entry &wavm )
  