Revert "build-lldb-mi: Skip building lldb-mi, as it's incompatible with current llvm versions"

This reverts commit 49950ae6be.

It's now compatible with current llvm versions.

build-lldb-mi.sh

@@ -16,9 +16,6 @@
 
 set -e
 
-echo Skipping LLDB MI, as it is incompatible with the current version of LLVM
-exit 0
-
 : ${LLDB_MI_VERSION:=96ec7799b67f8b3660ac5de4995cf1595c43273a}
 BUILDDIR=build
 unset HOST