[ruby/rubygems] Remove special behavior for rake

Fixes ruby/rubygems#9244

ruby/rubygems@7dc3d43d2e

Author: JasonLunn

lib/rubygems/ext/builder.rb

@@ -163,8 +163,6 @@ def initialize(spec, build_args = spec.build_args, target_rbconfig = Gem.target_
     @gem_dir    = spec.full_gem_path
     @target_rbconfig = target_rbconfig
     @build_jobs = build_jobs
-
-    @ran_rake = false
   end
 
   ##
@@ -177,7 +175,6 @@ def builder_for(extension) # :nodoc:
     when /configure/ then
       Gem::Ext::ConfigureBuilder
     when /rakefile/i, /mkrf_conf/i then
-      @ran_rake = true
       Gem::Ext::RakeBuilder
     when /CMakeLists.txt/ then
       Gem::Ext::CmakeBuilder.new
@@ -250,8 +247,6 @@ def build_extensions
     FileUtils.rm_f @spec.gem_build_complete_path
 
     @spec.extensions.each do |extension|
-      break if @ran_rake
-
       build_extension extension, dest_path
     end