compile.c: drop freezestring insn on String#-@

Followup to r62039 and remove the redundant freezestring
insn which was preventing deduplication from String#-@

* compile.c (iseq_peephole_optimize): drop freezestring insn on String#-@
  [ruby-core:85542] [Bug #14475]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62407 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 15 insertions, 0 deletions

diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index 83a3a1191a..8aa5c39323 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -568,6 +568,21 @@ class TestRubyOptimization < Test::Unit::TestCase
     end
   end
 
+  def test_peephole_dstr
+    code = "#{<<~'begin;'}\n#{<<~'end;'}"
+    begin;
+      exp = (-'a').object_id
+      z = 'a'
+      exp == (-"#{z}").object_id
+    end;
+    [ false, true ].each do |fsl|
+      iseq = RubyVM::InstructionSequence.compile(code,
+                                                 frozen_string_literal: fsl)
+      assert_equal(true, iseq.eval,
+                  "[ruby-core:85542] [Bug #14475] fsl: #{fsl}")
+    end
+  end
+
   def test_branch_condition_backquote
     bug = '[ruby-core:80740] [Bug #13444] redefined backquote should be called'
     class << self