[3.7] bpo-26544: Fixed implementation of platform.libc_ver(). (GH-7684). (GH-8193)

(cherry picked from commit 2a9b8babf0d09946ebebfdb2931cc0d3db5a1d3d)
diff --git a/Doc/library/platform.rst b/Doc/library/platform.rst
index f5cb52c..7d29dc1 100644
--- a/Doc/library/platform.rst
+++ b/Doc/library/platform.rst
@@ -270,7 +270,7 @@
    .. deprecated-removed:: 3.5 3.8
       See alternative like the `distro <https://pypi.org/project/distro>`_ package.
 
-.. function:: libc_ver(executable=sys.executable, lib='', version='', chunksize=2048)
+.. function:: libc_ver(executable=sys.executable, lib='', version='', chunksize=16384)
 
    Tries to determine the libc version against which the file executable (defaults
    to the Python interpreter) is linked.  Returns a tuple of strings ``(lib,