Implement an internal "assertShort" utility

Author: dwijnand

compiler/src/dotty/tools/package.scala

@@ -42,4 +42,11 @@ package object tools {
 
   def unreachable(x: Any = "<< this case was declared unreachable >>"): Nothing =
     throw new MatchError(x)
+
+  transparent inline def assertShort(inline assertion: Boolean, inline message: Any = null): Unit =
+    if !assertion then
+      val msg = message
+      val e = if msg == null then AssertionError() else AssertionError("assertion failed: " + msg)
+      e.setStackTrace(Array())
+      throw e
 }