ignore *.pdb
reduce mrb_open calls in mrbgem test
add comments at end of include guard
Merge pull request #1839 from cubicdaiya/issues/comment_include_guard

Add comments at end of include guard
Merge pull request #1838 from take-cheeze/reduce_mrb_open_in_test

Reduce mrb_open calls in mrbgem test.
set bit field for mrb_bool
set bool macro
Merge pull request #1841 from ksss/symbol-bool

set bool macro
Merge pull request #1840 from ksss/bit-field

set bit field for mrb_bool
add assertion method `assert_nothing_raised'
Merge pull request #1842 from ksss/assert_nothing_raised

add assertion method `assert_nothing_raised'
fix sym_intern argument type
Merge pull request #1845 from ksss/sym_intern-argument-type

fix sym_intern argument type
don't use of anonymous unions
remove deprecated register keyword
fix mrb_funcall calling
Merge pull request #1846 from take-cheeze/funcall_fix

Fix mrb_funcall calling.
Merge pull request #1843 from take-cheeze/suppress_warnings

Suppress warnings.
avoid mrb_string_value_cstr() to copy string between mrb_states in tests
Added a short description on how to add mruby gems to the compilation workflow.