Update git submodules

* Update prebuilts/clang/host/linux-x86 from branch 'master'
  to a7bd2b5154eb493007bd7f0b8f7730a70add777f
  - Remove clang-r344140
    
    We needed a point update to clang-r344140b.
    
    Test: N/A
    Change-Id: I5f2053c328d82ead932cb84c7e9d232cbb7c66aa
    
1 file changed