Merge pull request #2216 from iij/pr-mirb-link-termcap

libreadline requires libtermcap on OpenBSD.

mrbgems/mruby-bin-mirb/mrbgem.rake

@@ -5,6 +5,9 @@ MRuby::Gem::Specification.new('mruby-bin-mirb') do |spec|
 
   if spec.build.cc.search_header_path 'readline/readline.h'
     spec.cc.defines << "ENABLE_READLINE"
+    if spec.build.cc.search_header_path 'termcap.h'
+      spec.linker.libraries << 'termcap'
+    end
     spec.linker.libraries << 'readline'
   elsif spec.build.cc.search_header_path 'linenoise.h'
     spec.cc.defines << "ENABLE_LINENOISE"