Add test compilation to compileAll buildUnits() (#4900)

Update/move tests failing with Scala 3

Author: adkian-sifive

build.mill

@@ -40,12 +40,16 @@ object v extends Module {
 
   def buildUnits(): Seq[ScalaModule] = {
     scalaCrossVersions.flatMap { ver =>
-      Seq(chisel(ver), stdlib.cross(ver), unipublish)
+      Seq(
+        chisel(ver),
+        stdlib.cross(ver),
+        chisel(ver).test,
+        firrtl.cross(ver).test,
+        svsim.cross(ver).test,
+        unipublish
+      )
     } ++ scalaCrossVersions.filterNot(isScala3(_)).flatMap { ver2 =>
       Seq(
-        chisel(ver2).test,
-        firrtl.cross(ver2).test,
-        svsim.cross(ver2).test,
         `integration-tests`.cross(ver2).test,
         lit.utility.cross(ver2),
         panamaconverter.cross(ver2),

firrtl/src/test/scala/firrtlTests/options/ShellSpec.scala

@@ -4,7 +4,7 @@ package firrtlTests.options
 
 import firrtl.{annoSeqToSeq, seqToAnnoSeq, AnnotationSeq}
 import firrtl.annotations.NoTargetAnnotation
-import firrtl.options.Shell
+import firrtl.options.{BareShell, Shell}
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
@@ -16,7 +16,7 @@ class ShellSpec extends AnyFlatSpec with Matchers {
   case object D extends NoTargetAnnotation
   case object E extends NoTargetAnnotation
 
-  trait AlphabeticalCli { this: Shell =>
+  trait AlphabeticalCli extends BareShell { this: Shell =>
     parser.opt[Unit]('c', "c-option").unbounded().action((x, c) => C +: c)
     parser.opt[Unit]('d', "d-option").unbounded().action((x, c) => D +: c)
     parser.opt[Unit]('e', "e-option").unbounded().action((x, c) => E +: c)