Switch TypeApplications to inherited extensions

Author: som-snytt

compiler/src/dotty/tools/dotc/core/TypeApplications.scala

@@ -150,10 +150,10 @@ object TypeApplications:
 
 /** Extensions that model type application.
  */
-trait TypeApplications:
+class TypeApplications:
   import TypeApplications.*
 
-  extension (self: Type) { // braces to avoid indent
+  extension (self: Type) { // braces to avoid indenting existing code
   /** The type parameters of this type are:
    *  For a ClassInfo type, the type parameters of its class.
    *  For a typeref referring to a class, the type parameters of the class.

compiler/src/dotty/tools/dotc/core/TypeUtils.scala

@@ -11,7 +11,7 @@ import Names.Name
 import StdNames.nme
 import config.Feature
 
-class TypeUtils:
+class TypeUtils extends TypeApplications:
   /** A decorator that provides methods on types
    *  that are needed in the transformer pipeline.
    */

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -2134,11 +2134,7 @@ object Types extends TypeUtils {
     /** Is the `hash` of this type the same for all possible sequences of enclosing binders? */
     def hashIsStable: Boolean = true
   }
-  object Type:
-    // Extensions that model type application.
-    given TypeApplications()
-
-  // end Type
+  end Type
 
 // ----- Type categories ----------------------------------------------
 

compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -1897,9 +1897,9 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
           dotc.core.Symbols.defn.isTupleNType(self)
         def select(sym: Symbol): TypeRepr = self.select(sym)
         def appliedTo(targ: TypeRepr): TypeRepr =
-          Types.Type.given_TypeApplications.appliedTo(self)(targ)
+          Types.appliedTo(self)(targ)
         def appliedTo(targs: List[TypeRepr]): TypeRepr =
-          Types.Type.given_TypeApplications.appliedTo(self)(targs)
+          Types.appliedTo(self)(targs)
         def substituteTypes(from: List[Symbol], to: List[TypeRepr]): TypeRepr =
           self.subst(from, to)