Scala Compilation Breaks Due to FIRRTL -> Treadle Incompatability.

[davidbiancolin]

Users may see scala compilation issues that look like:

[error] <path>/target-design/chipyard/tools/treadle/src/main/scala/treadle/Driver.scala:6:8: object ExecutionOptionsManager is not a member of package firrtl 
[error] import firrtl.{AnnotationSeq, ExecutionOptionsManager, HasFirrtlOptions}
[error]        ^ 

Explanation quoted from #887:

Unfortunately, our firrtl-dependency overriding in chipyard's build.sbt has a hole wherein treadle pulls in a 1.5-SNAPSHOT from maven instead of our desired version of 1.4.1. Recently, a slew of deprecated APIs were removed in the 1.5-SNAPSHOT recently, leading treadle compilation to fail. As a result, FireSim master (and thus, the 1.12 release) and dev are broken. Unless i'm woefully mistaken, this should be true of Chipyard dev and at least its most recent release.

Note: This affects the latest release, 1.12, and possibly earlier releases. The workaround can also be found #887. We will fix this properly in the 1.13 release.