* configure.in (DLDFLAGS): use TARGET_ENTRY to specify an entry point
instead of TARGET which may contain non-identifer characters.
* lib/mkmf.rb (create_makefile): add TARGET_NAME which is the first
part consists of only word characters. [ruby-core:46248][Bug #6709]
merge revision(s) 36338: [Backport #6709]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@40093 b2dd03c8-39d4-4d8f-98ff-823fe69b080e