glibc: update to latest 2.27 commit (BZ #23927)

glibc: update to latest 2.27 commit (BZ #23927)

f6d0e8c36f Fix rwlock stall with PREFER_WRITER_NONRECURSIVE_NP (bug 23861)
2794474c65 powerpc: Add missing CFI register information (bug #23614)
d8ca7a0c71 Fix _dl_profile_fixup data-dependency issue (Bug 23690)
f1e211096b inet/tst-if_index-long: New test case for CVE-2018-19591 [BZ #23927]
4e9f34e54f support: Implement <support/descriptors.h> to track file descriptors
e75481a7a7 support: Close original descriptors in support_capture_subprocess
0f79dc0be3 support_quote_string: Do not use str parameter name
6b2dd53aa0 support: Implement support_quote_string
50477165b9 malloc: Add another test for tcache double free check.
4b246928bd malloc: tcache double free check

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>