mruby/mruby — pull request #437 by masamitsu-murase (2012-08-20 17:16:19+00:00)
Title: Modify irep initialization and GC.

Initialize mrb->irep array with 0 when realloc is called.
`root_scan_phase` expect that mrb->irep array should be initialized with 0.

Refer to irep_len and irep_capa when irep is marked by GC.
mrb->irep_len sometimes exceeds mrb->irep_capa in gc.c,
because irep_len is incremented in scope_new and then irep_capa is set in scope_finish via mrb_add_irep.
So irep_len can be larger than irep_capa if GC occurs just after scape_new is called.