Toolbox.compile can corrupt the internal state of the toolbox

[scabug]

import scala.reflect.runtime.universe._
import scala.tools.reflect.ToolBox

//case class Foo()  // Works if Foo is defined here instead

object HelloWorld {

  case class Foo()

  def main(args: Array[String]) {
    val tb = runtimeMirror(getClass.getClassLoader).mkToolBox()
    tb.compile(tb.parse("()")) // It works, if we comment this out

    //tb.typecheck(reify{()}.tree) // It works, if we uncomment this

    val foo = Foo()
    val exp = reify {foo: Foo}
    tb.typecheck(exp.tree)
  }
}

The typecheck in the last line fails with

Exception in thread "main" scala.tools.reflect.ToolBoxError: reflective typecheck has failed: type mismatch;
 found   : HelloWorld.(some other)Foo(in object HelloWorld)
 required: HelloWorld.Foo(in object HelloWorld)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.$anonfun$typecheck$1(ToolBoxFactory.scala:182)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.$anonfun$transformDuringTyper$4(ToolBoxFactory.scala:150)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.$anonfun$transformDuringTyper$3(ToolBoxFactory.scala:150)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.$anonfun$transformDuringTyper$1(ToolBoxFactory.scala:149)
	at scala.reflect.internal.Trees.wrappingIntoTerm(Trees.scala:1710)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.withWrapping$1(ToolBoxFactory.scala:119)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.transformDuringTyper(ToolBoxFactory.scala:120)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$ToolBoxGlobal.typecheck(ToolBoxFactory.scala:174)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl.$anonfun$typecheck$6(ToolBoxFactory.scala:379)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl$withCompilerApi$.apply(ToolBoxFactory.scala:359)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl.typecheck(ToolBoxFactory.scala:371)
	at scala.tools.reflect.ToolBoxFactory$ToolBoxImpl.typecheck(ToolBoxFactory.scala:26)
	at HelloWorld$.main(HelloWorld.scala:18)
	at HelloWorld.main(HelloWorld.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

A workaround is to call tb.typecheck on a very simple tree after every call to tb.compile.

Note that this is a similar bug to #8637, but it is different.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-9932?orig=1
Reporter: Gabor Gevay (ggevay)
Affected Versions: 2.11.8, 2.12.0-RC1