Use ChiselStage in Tests

This migrates the tests to Chisel 3.4/FIRRTL 1.4. This primarily
involves removing usages of deprecated methods including:

- Remove usages of Driver
- Use ChiselStage methods instead of BackendCompilationUtilities
  methods
- Use Dependency API for custom transforms
- Use extractCause to unpack StackError

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/test/scala/chiselTests/LiteralExtractorSpec.scala b/src/test/scala/chiselTests/LiteralExtractorSpec.scala
index 8735a0ae..0c485368 100644
--- a/src/test/scala/chiselTests/LiteralExtractorSpec.scala
+++ b/src/test/scala/chiselTests/LiteralExtractorSpec.scala
@@ -5,6 +5,7 @@ package chiselTests
 import chisel3._
 import chisel3.experimental._
 import chisel3.experimental.BundleLiterals._
+import chisel3.stage.ChiselStage
 import chisel3.testers.BasicTester
 import scala.collection.immutable.ListMap
 
@@ -50,7 +51,7 @@ class LiteralExtractorSpec extends ChiselFlatSpec {
   }
 
   "litOption" should "return None for non-literal hardware" in {
-    elaborate { new RawModule {
+    ChiselStage.elaborate { new RawModule {
       val a = Wire(UInt())
       assert(a.litOption == None)
     }}