Auto-sync with upstream master
    
    Upstream commit: 1e26d35193efbb29239c710a4c46a64708643320
    
    - malloc: Fix tcache leak after thread destruction (swbz#22111)
    - powerpc:  Fix IFUNC for memrchr.
    - aarch64: Optimized implementation of memmove for Qualcomm Falkor
    - Always do locking when iterating over list of streams (swbz#15142)
    - abort: Do not flush stdio streams (swbz#15436)