Initialize gems tmp when initializing bundled_gems_spec suite

That way it works even if no Bundler specs have run before.

spec/bundled_gems_spec.rb

@@ -24,6 +24,7 @@ RSpec.configure do |config|
     require_relative "bundler/support/rubygems_ext"
     Spec::Rubygems.test_setup
     Spec::Helpers.install_dev_bundler
+    FileUtils.mkdir_p Spec::Path.gem_path
   end
 
   config.around(:each) do |example|

spec/bundler/support/path.rb

@@ -195,31 +195,31 @@ module Spec
     end
 
     def gem_repo1(*args)
-      tmp("gems/remote1", *args)
+      gem_path("remote1", *args)
     end
 
     def gem_repo_missing(*args)
-      tmp("gems/missing", *args)
+      gem_path("missing", *args)
     end
 
     def gem_repo2(*args)
-      tmp("gems/remote2", *args)
+      gem_path("remote2", *args)
     end
 
     def gem_repo3(*args)
-      tmp("gems/remote3", *args)
+      gem_path("remote3", *args)
     end
 
     def gem_repo4(*args)
-      tmp("gems/remote4", *args)
+      gem_path("remote4", *args)
     end
 
     def security_repo(*args)
-      tmp("gems/security_repo", *args)
+      gem_path("security_repo", *args)
     end
 
     def system_gem_path(*path)
-      tmp("gems/system", *path)
+      gem_path("system", *path)
     end
 
     def pristine_system_gem_path
@@ -234,6 +234,10 @@ module Spec
       base.join(Gem.ruby_engine, RbConfig::CONFIG["ruby_version"])
     end
 
+    def gem_path(*args)
+      tmp("gems", *args)
+    end
+
     def lib_path(*args)
       tmp("libs", *args)
     end