Pull in r215352 from upstream llvm trunk (by Tim Northover):

  AArch64: add support for dynamic-loader relocations

  LLD needs them, and it's good to be able to print them properly when
  our object dumpers encounter them.

  Patch by Daniel Stewart.

This is needed for supporting the upgrade to a newer LLDB snapshot.
Pull in r216571 from upstream llvm trunk (by Zachary Turner):

  Fix some semantic usability issues with DynamicLibrary.

  This patch allows invalid DynamicLibrary instances to be
  constructed, and fixes the const-correctness of the isValid()
  method.

  No functional change.

This is needed for supporting the upgrade to a newer LLDB snapshot.
Pull in r221900 from upstream clang trunk (by Ed Maste):

  Hook up FreeBSD AArch64 support

  Patch from Andrew Turner.
Add patch files for r275152, r275153 and r275154.