[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(-)

For the macOS -bundle_loader linker option, we need a path to the
Ruby exectuable. $(RUBY) is not necessarily a path since it could
be a command line invocation. That happens during build with
runruby.rb and can happen post installation if the user passes
the --ruby option to a extconf.rb. Use $(bindir) to locate
the executable instead.

Before installation, $(bindir) doesn't exist, so we need to be
able to override $(BUILTRUBY) in such situations so test-spec
and bundled extensions could build. Use a new mkmf global,
$builtruby, to do this; set it in fake.rb and in extmk.rb.

Our build system is quite complex...

Not to refer outside the top build directory from rbconfig.

So that rubygems installer will work to build extension gems.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63459 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* tool/fake.rb: set "libdir" to build directory too, so that
  spec/ruby/optional/capi/spec_helper.rb can find libruby_so.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61490 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* tool/asm_parse.rb: add description
* tool/change_maker.rb: ditto
* tool/downloader.rb: ditto
* tool/eval.rb: ditto
* tool/expand-config.rb: ditto
* tool/extlibs.rb: ditto
* tool/fake.rb: ditto
* tool/file2lastrev.rb: ditto
* tool/gem-unpack.rb: ditto
* tool/gen_dummy_probes.rb: ditto
* tool/gen_ruby_tapset.rb: ditto
* tool/generic_erb.rb: ditto
* tool/id2token.rb: ditto
* tool/ifchange: ditto
* tool/insns2vm.rb: ditto
* tool/instruction.rb: ditto
* tool/jisx0208.rb: ditto
* tool/merger.rb: ditto
* tool/mkrunnable.rb: ditto
* tool/node_name.rb: ditto
* tool/parse.rb: ditto
* tool/rbinstall.rb: ditto
* tool/rbuninstall.rb: ditto
* tool/rmdirs: ditto
* tool/runruby.rb: ditto
* tool/strip-rdoc.rb: ditto
* tool/vcs.rb: ditto
* tool/vtlh.rb: ditto
* tool/ytab.sed: ditto
* tool/enc-unicode.rb: fix typo
* tool/mk_call_iseq_optimized.rb: ditto
* tool/update-deps: ditto
  [ruby-core:76215] [Bug #12539]
  by Noah Gibbs <the.codefolio.guy@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55564 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* tool/fake.rb: set "buildlibdir" to the build directory, instead
  of "builddir" which is filterd by MakeMakefile#configuration.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55156 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* tool/fake.rb (prehook): set "extout" in RbConfig to configure
  extension libraries.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54508 b2dd03c8-39d4-4d8f-98ff-823fe69b080e