Security update for glibc (moderate)

This update for glibc fixes the following security issues:

• CVE-2017-18269: An SSE2-optimized memmove implementation for i386 did
  not correctly perform the overlapping memory check if the source memory
  range spaned the middle of the address space, resulting in corrupt data
  being produced by the copy operation. This may have disclosed
  information to context-dependent attackers, resulted in a denial of
  service or code execution (bsc#1094150).
• CVE-2018-11236: Prevent integer overflow on 32-bit architectures when
  processing very long pathname arguments to the realpath function,
  leading to a stack-based buffer overflow (bsc#1094161).
• CVE-2018-11237: An AVX-512-optimized implementation of the mempcpy
  function may have writen data beyond the target buffer, leading to a
  buffer overflow in __mempcpy_avx512_no_vzeroupper (bsc#1092877,
  bsc#1094154).

This update was imported from the SUSE:SLE-15:Update update project.