bug#49983: grep-3.6.27-20b4 tests fail on Cygwin

[Gary Johnson]

I built grep-3.6.27-20b4 on a machine running up-to-date Cygwin
3.2.0 and Windows 10 Enterprise Version 10.0.18363 Build 18363.
Running "make check" resulted in the following summary.

    ============================================================================
    Testsuite summary for GNU grep 3.6.27-20b4
    ============================================================================
    # TOTAL: 117
    # PASS:  93
    # SKIP:  21
    # XFAIL: 2
    # FAIL:  1
    # XPASS: 0
    # ERROR: 0
    ============================================================================
    See tests/test-suite.log
    Please report to bug-grep@gnu.org
    ============================================================================

Here is a summary of the log.

    $ grep FAIL tests/test-suite.log
    # XFAIL: 2
    # FAIL:  1
    XFAIL: equiv-classes
    XFAIL equiv-classes (exit status: 1)
    FAIL: surrogate-pair
    FAIL surrogate-pair (exit status: 1)
    XFAIL: triple-backref
    XFAIL triple-backref (exit status: 1)

    $ wc tests/test-suite.log
      3000  11841 128417 tests/test-suite.log

The log is pretty big.  Would you like it posted here?

Regards,
Gary