Replacematcherror - catch exceptions and convert to internal error. (#424)

* Catch exceptions and convert to internal error.
We need to update the displayed message to incorporate a line number and text to be used for the issue.

* Cleanup exception handling/throwing.
Re-throw expected (or uncorrectable exceptions).
Provide Utils.getThrowable() to get the first (eldest) or last throwable in the chain.
Update tests to conform to FreeSpec protocol.

* Minor cleanup
Admit we've updated some deprecated ScalaTest methods.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/scala/firrtl/transforms/ConstantPropagation.scala b/src/main/scala/firrtl/transforms/ConstantPropagation.scala
index d08a7e6b..086f1cee 100644
--- a/src/main/scala/firrtl/transforms/ConstantPropagation.scala
+++ b/src/main/scala/firrtl/transforms/ConstantPropagation.scala
@@ -320,7 +320,7 @@ class ConstantPropagation extends Transform {
           case node: DefNode => node.copy(name = newName)
           case wire: DefWire => wire.copy(name = newName)
           case reg: DefRegister => reg.copy(name = newName)
-          case other => throwInternalError
+          case other => throwInternalError()
         }
       case other => other map backPropStmt
     }