Bump Scala to 2.12.14 and 2.13.6 (#2356)

This required also bumping sbt-scalafix to bring in a newer version of
semanticdb. The new version of semanticdb had an issue with a regex in
SMTLib, fixed by fixing the way '$' is escaped in the regex.

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        scala: [2.13.4, 2.12.13]
+        scala: [2.13.6, 2.12.14]
     container:
       image: ucbbar/chisel3-tools
       options: --user github --entrypoint /bin/bash
@@ -51,7 +51,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        scala: [2.13.4, 2.12.13]
+        scala: [2.13.6, 2.12.14]
     steps:
       - name: Checkout
         uses: actions/checkout@v2

build.sbt

@@ -4,8 +4,8 @@ enablePlugins(SiteScaladocPlugin)
 
 lazy val commonSettings = Seq(
   organization := "edu.berkeley.cs",
-  scalaVersion := "2.12.13",
-  crossScalaVersions := Seq("2.13.4", "2.12.13")
+  scalaVersion := "2.12.14",
+  crossScalaVersions := Seq("2.13.6", "2.12.14")
 )
 
 lazy val isAtLeastScala213 = Def.setting {

build.sc

@@ -10,7 +10,7 @@ import mill.contrib.buildinfo.BuildInfo
 
 import java.io.IOException
 
-object firrtl extends mill.Cross[firrtlCrossModule]("2.12.13", "2.13.4")
+object firrtl extends mill.Cross[firrtlCrossModule]("2.12.14", "2.13.6")
 
 class firrtlCrossModule(val crossScalaVersion: String) extends CrossSbtModule with ScalafmtModule with PublishModule with BuildInfo {
   override def millSourcePath = super.millSourcePath / os.up

project/plugins.sbt

@@ -18,7 +18,7 @@ addSbtPlugin("com.simplytyped" % "sbt-antlr4" % "0.8.2")
 
 addSbtPlugin("com.github.sbt" % "sbt-protobuf" % "0.7.0")
 
-addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.29")
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.30")
 
 addSbtPlugin("com.thoughtworks.sbt-api-mappings" % "sbt-api-mappings" % "3.0.0")
 

src/main/scala/firrtl/backends/experimental/smt/SMTLibSerializer.scala

@@ -145,7 +145,7 @@ object SMTLibSerializer {
     else { s"(ite ${serialize(e)} $bvOne $bvZero)" }
 
   // See <simple_symbol> definition in the Concrete Syntax Appendix of the SMTLib Spec
-  private val simple: Regex = raw"[a-zA-Z\+-/\*\=%\?!\.\$$_~&\^<>@][a-zA-Z0-9\+-/\*\=%\?!\.\$$_~&\^<>@]*".r
+  private val simple: Regex = raw"[a-zA-Z\+-/\*\=%\?!\.$$_~&\^<>@][a-zA-Z0-9\+-/\*\=%\?!\.$$_~&\^<>@]*".r
   def escapeIdentifier(name: String): String = name match {
     case simple() => name
     case _        => if (name.startsWith("|") && name.endsWith("|")) name else s"|$name|"