Don't force libraries used to build Ruby to its dependencies.

This, for example, allows to build Ruby against GMP, but doesn't force
libraries using Ruby to depend on GMP as well.

ruby.spec

@@ -21,7 +21,7 @@
 %endif
 
 
-%global release 90
+%global release 91
 %{!?release_string:%global release_string %{?development_release:0.}%{release}%{?development_release:.%{development_release}}%{?dist}}
 
 # The RubyGems library has to stay out of Ruby directory three, since the
@@ -148,6 +148,9 @@ Patch13: ruby-2.5.0-st.c-retry-operations-if-rebuilt.patch
 # https://bugzilla.redhat.com/show_bug.cgi?id=1547431
 # https://www.ruby-lang.org/en/news/2018/02/17/multiple-vulnerabilities-in-rubygems/
 Patch14: rubygems-2.5.0-multiple-vulnerabilities.patch
+# Don't force libraries used to build Ruby to its dependencies.
+# https://bugs.ruby-lang.org/issues/14422
+Patch15: ruby-2.6.0-library-options-to-MAINLIBS.patch
 
 Requires: %{name}-libs%{?_isa} = %{version}-%{release}
 Suggests: rubypick
@@ -535,6 +538,7 @@ rm -rf ext/fiddle/libffi*
 %patch12 -p1
 %patch13 -p1
 %patch14 -p0
+%patch15 -p1
 
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .
@@ -1084,6 +1088,9 @@ make check TESTS="-v $DISABLE_TESTS"
 %{gem_dir}/specifications/xmlrpc-%{xmlrpc_version}.gemspec
 
 %changelog
+* Mon Mar 05 2018 Vít Ondruch <vondruch@redhat.com> - 2.5.0-91
+- Don't force libraries used to build Ruby to its dependencies.
+
 * Thu Mar 01 2018 Vít Ondruch <vondruch@redhat.com> - 2.5.0-90
 - Drop GMP dependency.