Summary:
libstdc++ has some undefined behavior in bits/stl_tree.h that
has recently became excercised by some of the LLVM code.
Given that fixing libstdc++ will take years, adding the file
into a blacklist to fix bots seems like a necessity.
Reviewers: vitalybuka
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28686
llvm-svn: 291918