compiler-rt: move all __GLIBC_PREREQ into own header file Reviewers: eugenis Subscribers: dberris, #sanitizers, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D68177 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@373283 91177308-0d34-0410-b5e6-96231b3b80d8