Allow non-hot values in SeqLiterals

Closes #14460, #14751

Do not ensure that elements in a SeqLiteral are Hot.

Review by @liufengyun

Author: Xavientois

compiler/src/dotty/tools/dotc/transform/init/Semantic.scala

@@ -1234,7 +1234,7 @@ object Semantic {
 
       case SeqLiteral(elems, elemtpt) =>
         val ress = elems.map { elem =>
-          eval(elem, thisV, klass).ensureHot("May only use initialized value as method arguments", elem)
+          eval(elem, thisV, klass)
         }
         Result(Hot, ress.flatMap(_.errors))
 

tests/init/neg/enum-desugared.check

@@ -14,7 +14,7 @@ object ErrorMessageID {
   final val NoExplanationID = $new(1, "NoExplanationID")
 
   private[this] val $values: Array[ErrorMessageID] =
-    Array(this.LazyErrorId, this.NoExplanationID) // error // error
+    Array(this.LazyErrorId, this.NoExplanationID)
 
   def values: Array[ErrorMessageID] = $values.clone()
 

tests/init/neg/enum.check

@@ -1,6 +1,6 @@
 enum ErrorMessageID extends java.lang.Enum[ErrorMessageID] {
     case
         LazyErrorId,
-        NoExplanationID // error
+        NoExplanationID
     def errorNumber = ordinal - 2
 }

tests/init/neg/enum-desugared.scala renamed to tests/init/pos/error-enum-desugared.scala

@@ -0,0 +1,4 @@
+class Outer:
+  enum MyEnum {
+    case Case
+  }