commit 4267db0b265969d9b4638aea9b8034406bd1cd28
author Petr Hosek <phosek@chromium.org> Mon Jan 28 20:39:50 2019 +0000
committer Petr Hosek <phosek@chromium.org> Mon Jan 28 20:39:50 2019 +0000
tree 2c9f005cda3786e45fd338f71c1fd9f24030302e
parent 1d9cc94e8947f740404ca81a7038e487a9b8a20f

[libc++] Use runtime rather then compile-time glibc version check

glibc supports versioning, so it's possible to build against older
version and run against newer version. This is sometimes relied on
in practice, e.g. in Fuchsia build we build against older sysroot
(equivalent to Ubuntu Trusty) to cover the broadest possible range
of host systems, but that doesn't necessarily match the system that
binary is going to run on which may have newer version, in which case
the compile test used in curr_symbol is going to fail. Using runtime
check is more reliable.

Differential Revision: https://reviews.llvm.org/D56702

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@352425 91177308-0d34-0410-b5e6-96231b3b80d8