Merge: #22709: Use stdin as-is if it does not have a buffer attribute.

diff --cc Misc/NEWS
index 1c5d8005c42cdaa5d2d8243e0b6589b7823cacbf,c5261304a3be68329f14eda789f37dcc11836c4d..83c07f5a2e627b86c6a172922a77daa03c8c3715
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -128,21 -41,13 +128,24 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #25447: fileinput now uses sys.stdin as-is if it does not have a
+   buffer attribute (restores backward compatibility).
+ 
 +- Issue #25971: Optimized creating Fractions from floats by 2 times and from
 +  Decimals by 3 times.
 +
 +- Issue #25802: Document as deprecated the remaining implementations of
 +  importlib.abc.Loader.load_module().
 +
 +- Issue #25928: Add Decimal.as_integer_ratio().
 +
  - Issue #25447: Copying the lru_cache() wrapper object now always works,
 -  independedly from the type of the wrapped object (by returning the original
 +  independently from the type of the wrapped object (by returning the original
    object unchanged).
  
 +- Issue #25768: Have the functions in compileall return booleans instead of
 +  ints and add proper documentation and tests for the return values.
 +
  - Issue #24103: Fixed possible use after free in ElementTree.XMLPullParser.
  
  - Issue #25860: os.fwalk() no longer skips remaining directories when error