MSVC: compilation works again (+minor style fixes)
BUG: mrb_irep_free (access of freed memory)
fix wrong assertion fail when debug info contains more than one files
check returning line entry pointer is greater or equal to the first line entry pointer
add comment to mrb_assert in src/debug.c
Merge pull request #1496 from cremno/bug-debug-info-free

BUG: mrb_irep_free (access of freed memory)
Merge pull request #1497 from cremno/msvc-debug-info-feature

MSVC: compilation works again (+minor style fixes)
resolve conflict
fix line getting handler of line_ary
update filename before appending file debug info
remove unnecessary scope filename update
check file debug info is appended correctly
Merge pull request #1500 from take-cheeze/debug_info_file_updating

Fix insufficient preparation to call mrb_debug_info_append_file.
Fix checking return value of fread()
Merge pull request #1501 from iij/pr_fix_read_debug_section

Fix checking return value of fread()