merge revision(s) 57690-57694:

    rational.c: infinity in power

    * rational.c (nurat_expt): return 0 due to overflow.
      [ruby-core:79686] [Bug #13242]:
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    r57690 | nobu | 2017-02-23 10:15:27 +0900 (Thu, 23 Feb 2017) | 7 lines

    [DOC] {read,write}_nonblock with exception: false

    Update docs to reflect EOF behavior change of read_nonblock and
    write_nonblock when using `exception: false`.

    [Fix GH-1527]
    Author:    Russell Davis <[email protected]>
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    r57691 | nobu | 2017-02-23 10:54:13 +0900 (Thu, 23 Feb 2017) | 11 lines

    socket.rb: [DOC] fix nonblock methods

    * ext/socket/lib/socket.rb (BasicSocket#recv_nonblock): fix
      exception class and symbol.

    * ext/socket/lib/socket.rb (BasicSocket#recvmsg_nonblock): ditto.

    * ext/socket/lib/socket.rb (Socket#recvfrom_nonblock): fix the
      method name.

    * ext/socket/lib/socket.rb (UDPSocket#recvfrom_nonblock): both.
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    r57692 | nobu | 2017-02-23 11:00:28 +0900 (Thu, 23 Feb 2017) | 1 line

    [DOC] keyword argument _exception_
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    r57693 | nobu | 2017-02-23 11:11:16 +0900 (Thu, 23 Feb 2017) | 1 line

    [DOC] mark up literals
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    r57694 | nobu | 2017-02-23 11:40:17 +0900 (Thu, 23 Feb 2017) | 3 lines

    Revert r57690 except for read_nonblock

    https://.com/ruby/ruby/pull/1527#issuecomment-281867551

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57900 b2dd03c8-39d4-4d8f-98ff-823fe69b080e