Merge pull request scala#6973 from dotty-staging/fix-#6972

Fix scala#6972: Parially revert c53f465

Author: nicolasstucki

compiler/src/dotty/tools/dotc/config/JavaPlatform.scala

@@ -22,13 +22,10 @@ class JavaPlatform extends Platform {
 
   // The given symbol is a method with the right name and signature to be a runnable java program.
   def isMainMethod(sym: SymDenotation)(implicit ctx: Context): Boolean =
-    sym.name == nme.main &&
-    (sym.owner.is(Module) || sym.owner.isClass && !sym.owner.is(Trait) && sym.is(JavaStatic)) && {
-      sym.info match {
-        case MethodTpe(_, defn.ArrayOf(el) :: Nil, restpe) => el =:= defn.StringType && (restpe isRef defn.UnitClass)
-        case _ => false
-      }
-    }
+    (sym.name == nme.main) && (sym.info match {
+      case MethodTpe(_, defn.ArrayOf(el) :: Nil, restpe) => el =:= defn.StringType && (restpe isRef defn.UnitClass)
+      case _ => false
+    })
 
   /** Update classpath with a substituted subentry */
   def updateClassPath(subst: Map[ClassPath, ClassPath]): Unit = currentClassPath.get match {