Fix missing position exception

Otherwise, the compile crashes when there are macros.
Encountered in testing ScalaTest macros.

Author: liufengyun

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -898,7 +898,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
     def cast(tp: Type)(implicit ctx: Context): Tree = {
       assert(tp.isValueType, i"bad cast: $tree.asInstanceOf[$tp]")
       tree.select(if (ctx.erasedTypes) defn.Any_asInstanceOf else defn.Any_typeCast)
-        .appliedToType(tp)
+        .appliedToType(tp).withSpan(tree.span)
     }
 
     /** cast `tree` to `tp` (or its box/unbox/cast equivalent when after
@@ -908,7 +908,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
     def ensureConforms(tp: Type)(implicit ctx: Context): Tree =
       if (tree.tpe <:< tp) tree
       else if (!ctx.erasedTypes) cast(tp)
-      else Erasure.Boxing.adaptToType(tree, tp)
+      else Erasure.Boxing.adaptToType(tree, tp).withSpan(tree.span)
 
     /** `tree ne null` (might need a cast to be type correct) */
     def testNotNull(implicit ctx: Context): Tree = {
@@ -918,7 +918,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
         Typed(tree, TypeTree(defn.AnyRefType))
       }
       else tree.ensureConforms(defn.ObjectType)
-      receiver.select(defn.Object_ne).appliedTo(nullLiteral)
+      receiver.select(defn.Object_ne).appliedTo(nullLiteral).withSpan(tree.span)
     }
 
     /** If inititializer tree is `_', the default value of its type,
@@ -929,11 +929,11 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
 
     /** `this && that`, for boolean trees `this`, `that` */
     def and(that: Tree)(implicit ctx: Context): Tree =
-      tree.select(defn.Boolean_&&).appliedTo(that)
+      tree.select(defn.Boolean_&&).appliedTo(that).withSpan(tree.span)
 
     /** `this || that`, for boolean trees `this`, `that` */
     def or(that: Tree)(implicit ctx: Context): Tree =
-      tree.select(defn.Boolean_||).appliedTo(that)
+      tree.select(defn.Boolean_||).appliedTo(that).withSpan(tree.span)
 
     /** The translation of `tree = rhs`.
      *  This is either the tree as an assignment, or a setter call.