Add test of $0 value in bin/mruby related to #2103 .
OP_SEND refactoring
reduce the init size of stack
Merge pull request #2106 from mirichi/enhance

OP_SEND refactoring
bug fixed
Add Array#insert
Array#insert: simpler (and faster) implementation; ref #2107
Merge pull request #2105 from take-cheeze/issue_2103_test

Add test of $0 value in bin/mruby related to #2103 .
Implement default gem info to use when there is no depending gem is defined.
Merge remote-tracking branch 'remotes/mruby/master' into enhance
fixed.
Merge pull request #2109 from mirichi/enhance

reduce the init area of stack
Merge pull request #2108 from take-cheeze/default_gem_info

Implement default gem info to use when there is no depending gem loaded.
Fix MSVC warning for gc.c
Merge pull request #2111 from kyab/fix_msvc_warning_gc.c

Fix MSVC warning for gc.c
Update documentation of `MRuby::Gem::Specification#add_dependency`.
Merge pull request #2113 from take-cheeze/add_dependency_doc

Update documentation of `MRuby::Gem::Specification#add_dependency`.
Add Array#bsearch
Array#fill fix bug when argument use range object
Array#fill use `kind_of?` instead of `respond_to?`