(https://github.com/ruby/io-wait/pull/25)

https://github.com/ruby/io-wait/commit/e5854b46c7

Ref: https://github.com/mikel/mail/pull/1439

Some gems depend on io-wait, but still support older rubies,
so they have to chose between droping support or not listing io-wait.

But io-wait could act a a noop on older rubies.

https://github.com/ruby/io-wait/commit/75fcb74c32

https://github.com/ruby/io-wait/commit/898248931f

g -L frozen_string_literal ext/**/*.rb|xargs ruby -Ka -e'ARGV.each{|fn|puts
fn;open(fn,"r+"){|f|s=f.read.sub(/\A(#!.*\n)?(#.*coding.*\n)?/,"\\&#
frozen_string_literal: false\n");f.rewind;f.write s}}'

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53143 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  cygwin.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19947 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@17558 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@10945 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@8783 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* ext/extmk.rb (extmake): set library name as source file name in
  Init_ext().  [ruby-dev:21137]

* lib/mkmf.rb (Logging::postpone): postpone logging messages after
  heading message as the result of the block.

* lib/mkmf.rb (macro_defined?): append newline to src unless ended
  with it.

* lib/mkmf.rb (have_library): allow nil function name to just
  append a library.  (ruby-bugs:PR#1083)

* lib/mkmf.rb (pkg_config): should append additional libraries to
  $libs but not $LIBS.  [ruby-dev:21137]

* ext/io/wait/extconf.rb: check DOSISH macro instead of platform.

* ext/digest/sha1/extconf.rb: have_library already appends library
  name.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4337 b2dd03c8-39d4-4d8f-98ff-823fe69b080e