[Bug #19967] Reset `LIBPATHENV` env after started

	Not to affect other tools invoked as child processes.
	---
	 common.mk            | 3 ++-
	 template/Makefile.in | 3 +++
	 template/fake.rb.in  | 3 +++
	 tool/fake.rb         | 8 ++++++++
	 4 files changed, 16 insertions(+), 1 deletion(-)

	[Bug #19967] Revert "configure.ac: LIBPATHENV on macOS"

	This reverts commit 1961c786aab243b3eb60e7238224e87975d88056.  These
	environment variables should no longer propagate to child processes.
	---
	 configure.ac | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

	[Bug #19967] Delete real path

	---
	 tool/fake.rb | 3 ++-
	 1 file changed, 2 insertions(+), 1 deletion(-)

	[Bug #19967] Ignore library before build

	---
	 tool/fake.rb | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

This reverts commit 4b16259d1d6f408a88ac2c8d04ed78e87bdeda9f.

	[Travis] make `.bundle` directory writable

	To create gem files from sources under `gems/src` for tests.
	---
	 .travis.yml | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

	Fix support for dynamic keys. (#8273)

	* Skip RBS test.
	---
	 cont.c                               |  8 +++-----
	 spec/ruby/core/fiber/storage_spec.rb | 14 ++++++++++++++
	 tool/rbs_skip_tests                  |  2 ++
	 3 files changed, 19 insertions(+), 5 deletions(-)