Make --import flag work again (#2502)

Fixes #2485

We take the `config.imports` field and pass it to
`MillIvy.processMillIvyDepSignature` inside `ivyDeps`. This was
overlooked in #2377, but seems
easy enough to put back

Honestly not super sure how to test this. But when I run

```
./mill -i dev.run example/tasks/3-anonymous-tasks -i --import ivy:com.lihaoyi::mill-contrib-bloop:0.11.0-M8  mill.contrib.bloop.Bloop/install
```

On main branch, I get 

```
Cannot resolve external module mill.contrib.bloop.Bloop
```

On this PR I get

```
java.lang.NoSuchMethodError: 'java.lang.ThreadLocal mill.eval.Evaluator$.currentEvaluator()'
    mill.contrib.bloop.Bloop$$anonfun$$lessinit$greater$1.apply(Bloop.scala:8)
    mill.contrib.bloop.Bloop$$anonfun$$lessinit$greater$1.apply(Bloop.scala:8)
```

Seems like there's a binary incompatibility, but at least the `--import`
flag took effect?

Author: lihaoyi

runner/src/mill/runner/MillBuildBootstrap.scala

@@ -72,7 +72,12 @@ class MillBuildBootstrap(
         } else {
 
           val bootstrapModule =
-            new MillBuildRootModule.BootstrapModule(projectRoot, recRoot(depth), millBootClasspath)(
+            new MillBuildRootModule.BootstrapModule(
+              projectRoot,
+              recRoot(depth),
+              millBootClasspath,
+              config.imports.collect { case s"ivy:$rest" => rest }
+            )(
               mill.main.RootModule.Info(
                 recRoot(depth),
                 Discover[MillBuildRootModule.BootstrapModule]

runner/src/mill/runner/MillBuildRootModule.scala

@@ -84,22 +84,23 @@ class MillBuildRootModule()(implicit
     }
   }
 
+  def cliImports = T.input { millBuildRootModuleInfo.cliImports }
+
   override def ivyDeps = T {
     Agg.from(
       MillIvy.processMillIvyDepSignature(parseBuildFiles().ivyDeps)
-        .map(str =>
-          mill.scalalib.Dep.parse(
-            str
-              .replace("$MILL_VERSION", mill.BuildInfo.millVersion)
-              .replace("${MILL_VERSION}", mill.BuildInfo.millVersion)
-              .replace("$MILL_BIN_PLATFORM", mill.BuildInfo.millBinPlatform)
-              .replace("${MILL_BIN_PLATFORM}", mill.BuildInfo.millBinPlatform)
-          )
-        )
+        .map(mill.scalalib.Dep.parse)
     ) ++
       Seq(ivy"com.lihaoyi::mill-moduledefs:${Versions.millModuledefsVersion}")
   }
 
+  override def runIvyDeps = T {
+    Agg.from(
+      MillIvy.processMillIvyDepSignature(cliImports().toSet)
+        .map(mill.scalalib.Dep.parse)
+    )
+  }
+
   override def generatedSources: T[Seq[PathRef]] = T {
     generateScriptSources()
   }
@@ -114,7 +115,8 @@ class MillBuildRootModule()(implicit
         parsed.seenScripts,
         T.dest,
         millBuildRootModuleInfo.enclosingClasspath,
-        millBuildRootModuleInfo.topLevelProjectRoot
+        millBuildRootModuleInfo.topLevelProjectRoot,
+        millBuildRootModuleInfo.cliImports
       )
       Result.Success(Seq(PathRef(T.dest)))
     }
@@ -168,13 +170,15 @@ object MillBuildRootModule {
   class BootstrapModule(
       topLevelProjectRoot0: os.Path,
       projectRoot: os.Path,
-      enclosingClasspath: Seq[os.Path]
+      enclosingClasspath: Seq[os.Path],
+      cliImports: Seq[String]
   )(implicit baseModuleInfo: RootModule.Info) extends RootModule {
 
     implicit private def millBuildRootModuleInfo = MillBuildRootModule.Info(
       enclosingClasspath,
       projectRoot,
-      topLevelProjectRoot0
+      topLevelProjectRoot0,
+      cliImports
     )
     object build extends MillBuildRootModule
 
@@ -185,7 +189,8 @@ object MillBuildRootModule {
   case class Info(
       enclosingClasspath: Seq[os.Path],
       projectRoot: os.Path,
-      topLevelProjectRoot: os.Path
+      topLevelProjectRoot: os.Path,
+      cliImports: Seq[String]
   )
 
   def parseBuildFiles(millBuildRootModuleInfo: MillBuildRootModule.Info) = {
@@ -201,7 +206,8 @@ object MillBuildRootModule {
       scriptCode: Map[os.Path, String],
       targetDest: os.Path,
       enclosingClasspath: Seq[os.Path],
-      millTopLevelProjectRoot: os.Path
+      millTopLevelProjectRoot: os.Path,
+      cliImports: Seq[String]
   ) = {
     for (scriptSource <- scriptSources) {
       val relative = scriptSource.path.relativeTo(base)
@@ -214,7 +220,8 @@ object MillBuildRootModule {
         scriptSource.path.baseName,
         enclosingClasspath,
         millTopLevelProjectRoot,
-        scriptSource.path
+        scriptSource.path,
+        cliImports
       ) +
         scriptCode(scriptSource.path) +
         MillBuildRootModule.bottom
@@ -230,7 +237,8 @@ object MillBuildRootModule {
       name: String,
       enclosingClasspath: Seq[os.Path],
       millTopLevelProjectRoot: os.Path,
-      originalFilePath: os.Path
+      originalFilePath: os.Path,
+      cliImports: Seq[String]
   ) = {
 
     val superClass =
@@ -259,7 +267,8 @@ object MillBuildRootModule {
        |  implicit val millBuildRootModuleInfo: _root_.mill.runner.MillBuildRootModule.Info = _root_.mill.runner.MillBuildRootModule.Info(
        |    ${enclosingClasspath.map(p => literalize(p.toString))}.map(_root_.os.Path(_)),
        |    _root_.os.Path(${literalize(base.toString)}),
-       |    _root_.os.Path(${literalize(millTopLevelProjectRoot.toString)})
+       |    _root_.os.Path(${literalize(millTopLevelProjectRoot.toString)}),
+       |    _root_.scala.Seq(${cliImports.map(literalize(_)).mkString(", ")})
        |  )
        |  implicit val millBaseModuleInfo: _root_.mill.main.RootModule.Info = _root_.mill.main.RootModule.Info(
        |    millBuildRootModuleInfo.projectRoot,