Fix portability of bignum in ISeq Binary Format

- Unless `sizeof(BDIGIT) == 4`, (8-byte integer not available), the
  size to be loaded was wrong.
- Since `BDIGIT`s are dumped as raw binary, the loaded byte order was
  inverted unless little-endian.

1 files changed, 7 insertions, 0 deletions

diff --git a/test/ruby/test_iseq.rb b/test/ruby/test_iseq.rb
index 6a1a1ea8c1..f05d067ac2 100644
--- a/test/ruby/test_iseq.rb
+++ b/test/ruby/test_iseq.rb
@@ -791,4 +791,11 @@ class TestISeq < Test::Unit::TestCase
       end
     end;
   end
+
+  def test_ibf_bignum
+    iseq = RubyVM::InstructionSequence.compile("0x0"+"_0123_4567_89ab_cdef"*5)
+    expected = iseq.eval
+    result = RubyVM::InstructionSequence.load_from_binary(iseq.to_binary).eval
+    assert_equal expected, result, proc {sprintf("expected: %x, result: %x", expected, result)}
+  end
 end