The pkg/front_end/tool/fasta_perf.dart benchmark used to require
runtime/lib in order to run but this directory is no longer required.
This change removes the check for whether it exists and then removes the
directory in SDK benchmark builds to avoid VM source code littering the
benchmark builds and blurring the distinction between build inputs and
build outputs.
Change-Id: Ibb02ce3bd6e4a65421c2bdd444ef0f78887fffa1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/164966
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Jonas Termansen
5f459d0228