[docs] Stop advertising 'make update'. It isn't implemented in CMake and
seems unlikely to be added. It also doesn't seem like it should be part
of the build system at all (consider out-of-tree builds).

We should probably add nice, easy tool for this that works both for svn
client trees and git-svn client trees, but it probably won't be spelled
"make update".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202430 91177308-0d34-0410-b5e6-96231b3b80d8
Drive-by comment fix. This regalloc comment was not accurate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202432 91177308-0d34-0410-b5e6-96231b3b80d8
Provide a target override for the latest regalloc heuristic.

This is a temporary workaround for native arm linux builds:
PR18996: Changing regalloc order breaks "lencod" on native arm linux builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202433 91177308-0d34-0410-b5e6-96231b3b80d8