Failed to build from source

Description:

Build failed.
Just using makepkg can reproduce.

Additional info:

• package version(s): 0.0.8-13
• Logs:

In file included from ../freehdl/std-vhdl-types.hh:16,
                 from error.cc:4:
../freehdl/kernel-acl.hh: In static member function 'static void acl::operator delete(void*)':
../freehdl/kernel-acl.hh:95:18: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   95 |     register int s = ((acl*)a)->get_header().size;
      |                  ^
../freehdl/std-vhdl-types.hh: In function 'integer op_mod(integer, integer)':
../freehdl/std-vhdl-types.hh:261:16: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  261 |   register int tmp = a % b;
      |                ^~~
../freehdl/std-vhdl-types.hh: In function 'A concat(array_info*, const A&, const A&)':
../freehdl/std-vhdl-types.hh:1497:58: error: expression cannot be used as a function
 1497 |   const int mem_size = length * ainfo->element_type->size();
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~^~
make[1]: *** [Makefile:423：libfreehdl_kernel_la-error.lo] 错误 1
make[1]: 离开目录“/home/rain/freehdl/src/freehdl-0.0.8/kernel”
make: *** [Makefile:350：all-recursive] 错误 1