Add splice-position test

Author: mbovel

tests/run/splice-position.check

@@ -0,0 +1,2 @@
+Test$.main(Test.scala:3)
+Test$.main(Test.scala:4)

tests/run/splice-position/Test.scala

@@ -0,0 +1,4 @@
+object Test:
+  def main(args: Array[String]) =
+    try assertTrue(1 == 2) catch e => println(e.getStackTrace()(0))
+    try assertTrue(1 == 3) catch e => println(e.getStackTrace()(0))

tests/run/splice-position/macros.scala

@@ -0,0 +1,7 @@
+import scala.quoted.{Quotes, Expr, quotes}
+
+inline def assertTrue(cond: Boolean) =
+  ${ assertTrueImpl('cond) }
+
+def assertTrueImpl(cond: Expr[Boolean])(using Quotes) =
+  '{ if (!$cond) throw new Error(${'{""}}) }