enumerator.c: force hash values fixable

* enumerator.c (arith_seq_hash): force hash values fixable on
  LLP64 environment.  [ruby-core:92190] [Bug #15755]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67466 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: nobu

enumerator.c

@@ -3345,7 +3345,7 @@ arith_seq_hash(VALUE self)
     hash = rb_hash_uint(hash, NUM2LONG(v));
     hash = rb_hash_end(hash);
 
-    return LONG2FIX(hash);
+    return ST2FIX(hash);
 }
 
 #define NUM_GE(x, y) RTEST(rb_num_coerce_relop((x), (y), idGE))

test/ruby/test_arithmetic_sequence.rb

@@ -127,6 +127,7 @@ def test_hash
     assert_equal(seq.hash, seq.hash)
     assert_equal(seq.hash, 1.step.hash)
     assert_equal(seq.hash, 1.step(nil).hash)
+    assert_kind_of(String, seq.hash.to_s)
   end
 
   def test_first