Initialize quote cache on tasty run

This fixes #13919

Author: Jakob Odersky

sbt-test/sbt-dotty/tasty-inspector-cache/build.sbt

@@ -0,0 +1,24 @@
+lazy val dottyVersion = sys.props("plugin.scalaVersion")
+
+lazy val lib = project
+  .in(file("lib"))
+  .settings(
+    scalaVersion := dottyVersion
+  )
+
+val jarDest = file("target") / "app.jar"
+
+val runTest = Def.taskKey[Unit]("run tests")
+
+lazy val inspector = project
+  .in(file("inspector"))
+  .settings(
+    scalaVersion := dottyVersion,
+    libraryDependencies += "org.scala-lang" %% "scala3-tasty-inspector" % scalaVersion.value,
+    runTest :=
+      Def.sequential(
+        Def.task(IO.copyFile((lib/Compile/packageBin).value, jarDest)),
+        (Compile/run).toTask(" " + jarDest.getAbsolutePath)
+      ).value
+  )
+  .dependsOn(lib)

sbt-test/sbt-dotty/tasty-inspector-cache/inspector/src/main/scala/main.scala

@@ -0,0 +1,14 @@
+import scala.quoted.Quotes
+import scala.quoted.quotes
+import scala.tasty.inspector as ins
+
+// Test for https://github.com/lampepfl/dotty/issues/13919
+class MyInspector extends ins.Inspector:
+  def inspect(using Quotes)(tastys: List[ins.Tasty[quotes.type]]): Unit =
+    import quotes.reflect._
+    TypeRepr.of[Int]
+    TypeRepr.of[String]
+
+
+@main def main(args: String*): Unit =
+  ins.TastyInspector.inspectTastyFilesInJar(args.head)(new MyInspector)

sbt-test/sbt-dotty/tasty-inspector-cache/lib/src/main/scala/dummy.scala

@@ -0,0 +1 @@
+class Dummy // we need at least one file for the tasty inspector to run

sbt-test/sbt-dotty/tasty-inspector-cache/test

@@ -0,0 +1 @@
+> inspector/runTest

tasty-inspector/src/scala/tasty/inspector/TastyInspector.scala

@@ -10,6 +10,7 @@ import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.Mode
 import dotty.tools.dotc.core.Phases.Phase
 import dotty.tools.dotc.fromtasty._
+import dotty.tools.dotc.quoted.QuotesCache
 import dotty.tools.dotc.util.ClasspathFromClassloader
 import dotty.tools.dotc.CompilationUnit
 import dotty.tools.unsupported
@@ -64,7 +65,11 @@ object TastyInspector:
     class TastyInspectorPhase extends Phase:
       override def phaseName: String = "tastyInspector"
 
-      override def runOn(units: List[CompilationUnit])(using Context): List[CompilationUnit] =
+      override def runOn(units: List[CompilationUnit])(using ctx0: Context): List[CompilationUnit] =
+        val ctx = QuotesCache.init(ctx0.fresh)
+        runOnImpl(units)(using ctx)
+
+      private def runOnImpl(units: List[CompilationUnit])(using Context): List[CompilationUnit] =
         val quotesImpl = QuotesImpl()
         class TastyImpl(val path: String, val ast: quotesImpl.reflect.Tree) extends Tasty[quotesImpl.type] {
           val quotes = quotesImpl