Introduce VecLiterals (#1834)

This PR provides for support for Vec literals. They can be one of two forms
Inferred:
```
Vec.Lit(0x1.U, 0x2.U)
```
or explicit:
```
Vec(2, UInt(4.W)).Lit(0 -> 0x1.U, 1 -> 0x2.U)
```
- Explicit form allows for partial, or sparse, literals.
- Vec literals can be used as Register initializers
- Arbitrary nesting (consistent with type constraints is allowed)

1 files changed, 14 insertions, 11 deletions

diff --git a/src/test/scala/chiselTests/ChiselSpec.scala b/src/test/scala/chiselTests/ChiselSpec.scala
index 8df680d6..9503089a 100644
--- a/src/test/scala/chiselTests/ChiselSpec.scala
+++ b/src/test/scala/chiselTests/ChiselSpec.scala
@@ -2,22 +2,22 @@
 
 package chiselTests
 
-import org.scalatest._
-import org.scalatest.prop._
-import org.scalatest.flatspec.AnyFlatSpec
-import org.scalacheck._
 import chisel3._
-import chisel3.stage.{ChiselGeneratorAnnotation, ChiselStage}
+import chisel3.aop.Aspect
+import chisel3.stage.{ChiselGeneratorAnnotation, ChiselStage, NoRunFirrtlCompilerAnnotation, PrintFullStackTraceAnnotation}
 import chisel3.testers._
-import firrtl.{AnnotationSeq, CommonOptions, EmittedVerilogCircuitAnnotation, ExecutionOptionsManager, FirrtlExecutionFailure, FirrtlExecutionSuccess, HasFirrtlOptions}
-import firrtl.annotations.{Annotation, DeletedAnnotation}
+import firrtl.annotations.Annotation
 import firrtl.util.BackendCompilationUtilities
+import firrtl.{AnnotationSeq, EmittedVerilogCircuitAnnotation}
+import org.scalacheck._
+import org.scalatest._
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.freespec.AnyFreeSpec
+import org.scalatest.matchers.should._
+import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
+
 import java.io.ByteArrayOutputStream
 import java.security.Permission
-
-import chisel3.aop.Aspect
-import chisel3.stage.{ChiselGeneratorAnnotation, ChiselStage, NoRunFirrtlCompilerAnnotation, PrintFullStackTraceAnnotation}
-import org.scalatestplus.scalacheck.ScalaCheckPropertyChecks
 import scala.reflect.ClassTag
 
 /** Common utility functions for Chisel unit tests. */
@@ -90,6 +90,9 @@ trait ChiselRunners extends Assertions with BackendCompilationUtilities {
 /** Spec base class for BDD-style testers. */
 abstract class ChiselFlatSpec extends AnyFlatSpec with ChiselRunners with Matchers
 
+/** Spec base class for BDD-style testers. */
+abstract class ChiselFreeSpec extends AnyFreeSpec with ChiselRunners with Matchers
+
 /** Spec base class for property-based testers. */
 abstract class ChiselPropSpec extends PropSpec with ChiselRunners with ScalaCheckPropertyChecks with Matchers {