compile.c: check funcptr

* compile.c (iseq_build_from_ary_body): cannot load dumped funcptr.

* iseq.c (iseq_data_to_ary): cannot dump funcptr.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48857 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
iseq.c: show function name if possible

* iseq.c (rb_insn_operand_intern): show the name of the nearest
  run-time symbol if possible.

* compile.c (insn_data_to_s_detail): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48858 b2dd03c8-39d4-4d8f-98ff-823fe69b080e