io.c: no envp if no spawnve

* io.c (pipe_open): envp is not used if only spawnv is defined right
  now.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38835 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
process.c: suppress warnings

* process.c (p_uid_change_privilege, p_gid_change_privilege): suppress
  set-but-unsed warnings.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38836 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
object.c: two literals

* object.c (rb_mod_to_s): concatenate two literals.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38837 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
object.c: CLASS_OR_MODULE_P

* object.c (rb_mod_to_s, rb_class_inherited_p, rb_mod_ge, rb_mod_cmp):
  use BUILTIN_TYPE() instead of TYPE() for optimization.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38838 b2dd03c8-39d4-4d8f-98ff-823fe69b080e