debug.c: new debug line information format `mrb_debug_line_packed_map`.

It uses BER number compression of delta of instruction positions and line
numbers. BER compression is a variable length number representation.

* `mrb_debug_line_ary`: array of line numbers represented in `uint16_t`.
  `[lineno, lineno, ...]`

* `mrb_debug_line_flat_map`: array of `mrb_irep_debug_info_line`, which
  is `struct {uint32_t pos; uint16_t lineno}`, for each line.

* `mrb_debug_line_packed_map` [new]: sequence of BER compressed 2
  numbers, `pos_delta, lineno_delta`. Deltas are differences from
  previous values (starting `0`). `line_entry_counts` represents total
  length of a packed map string for this type.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/dump.c b/src/dump.c
index 0b4200795..628c3dbc4 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -413,6 +413,10 @@ get_debug_record_size(mrb_state *mrb, const mrb_irep *irep)
         ret += (sizeof(uint32_t) + sizeof(uint16_t)) * (size_t)(file->line_entry_count);
         break;
 
+      case mrb_debug_line_packed_map:
+        ret += (size_t)(file->line_entry_count);
+        break;
+
       default: mrb_assert(0); break;
     }
   }
@@ -507,6 +511,11 @@ write_debug_record_1(mrb_state *mrb, const mrb_irep *irep, uint8_t *bin, mrb_sym
         }
       } break;
 
+      case mrb_debug_line_packed_map: {
+        memcpy(cur, file->lines.packed_map, file->line_entry_count);
+        cur += file->line_entry_count;
+      } break;
+
       default: mrb_assert(0); break;
     }
   }