Keep track of the originally allocated environ

We need to keep a pointer to the originally allocated environ because
adding more environment variables can cause it to be changed to something
else.

For example:

    100.times do |i|
      ENV["FOO#{i}"] = "1"
    end

Causes Valgrind to report:

    312 bytes in 1 blocks are definitely lost in loss record 9 of 13
      at 0x484D444: calloc (vg_replace_malloc.c:1340)
      by 0x1884F8: calloc1 (gc.c:1844)
      by 0x1884F8: objspace_xcalloc (gc.c:12202)
      by 0x1884F8: ruby_xcalloc_body (gc.c:12209)
      by 0x4204DD: ruby_init_setproctitle (setproctitle.c:119)
      by 0x27DDF4: ruby_process_options (ruby.c:3101)
      by 0x160BD1: ruby_options (eval.c:117)
      by 0x15B96E: rb_main (main.c:40)
      by 0x15B96E: main (main.c:59)

0 files changed, 0 insertions, 0 deletions