benchmark/bm_hash_aref_sym*.rb: force static symbols

Dynamic symbols hash more slowly because they need extra method
dispatch in rb_any_hash.  I am not sure if dynamic symbols are
a realistic use case as hash keys, so this commit only
restores performance when comparing against versions of Ruby
which lack dsyms.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Thu Oct  9 12:40:28 2014  Eric Wong  <e@80x24.org>
+
+	* benchmark/bm_hash_aref_sym*.rb: force static symbols
+
 Thu Oct  9 12:38:28 2014  Eric Wong  <e@80x24.org>
 
 	* hash.c (rb_any_hash): remove unnecessary dsym check

benchmark/bm_hash_aref_sym.rb

@@ -1,4 +1,9 @@
 h = {}
-syms = ('a'..'z').to_a.map(&:to_sym)
+syms = ('a'..'z').to_a
+begin
+  syms = eval("%i[#{syms.join(' ')}]")
+rescue SyntaxError # <= 1.9.3
+  syms.map!(&:to_sym)
+end
 syms.each { |s| h[s] = s }
 200_000.times { syms.each { |s| h[s] } }

benchmark/bm_hash_aref_sym_long.rb

@@ -3,6 +3,11 @@ syms = %w[puts warn syswrite write stat bacon lettuce tomato
 some symbols in this array may already be interned  others should not be
 hash browns make good breakfast but not cooked using prime numbers
 shift for division entries delete_if keys exist?
-].map!(&:to_sym)
+]
+begin
+  syms = eval("%i[#{syms.join(' ')}]")
+rescue SyntaxError # <= 1.9.3
+  syms.map!(&:to_sym)
+end
 syms.each { |s| h[s] = s }
 200_000.times { syms.each { |s| h[s] } }