Re: [RFC] deduplicate strings VM-wide in Ruby 2.5+

[Eric Wong <e@80x24.org>]

Since 'mkmf' is already in the fstring table as that exists in
the source; so I'll at least have to squash this on top for
Ruby <=2.5:

diff --git a/ext/unicorn_http/extconf.rb b/ext/unicorn_http/extconf.rb
index 5b7a8ca..d5f81fb 100644
--- a/ext/unicorn_http/extconf.rb
+++ b/ext/unicorn_http/extconf.rb
@@ -26,8 +26,11 @@
 
 message('checking if Hash#[]= (rb_hash_aset) dedupes... ')
 h = {}
-h[%w(m k m f).join('')] = :foo
-if 'mkmf'.freeze.equal?(h.keys[0])
+x = {}
+r = rand.to_s
+h[%W(#{r}).join('')] = :foo
+x[%W(#{r}).join('')] = :foo
+if x.keys[0].equal?(h.keys[0])
   $CPPFLAGS += ' -DHASH_ASET_DEDUPE=1 '
   message("yes\n")
 else