Move relaxed context to a function

Author: noti0na1

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

@@ -712,6 +712,9 @@ object Contexts {
 
       def withNotNullInfos(infos: List[NotNullInfo]): Context =
         if c.notNullInfos eq infos then c else c.fresh.setNotNullInfos(infos)
+
+      def relaxedOverrideContext: Context =
+        c.withModeBits(c.mode &~ Mode.SafeNulls | Mode.RelaxedOverriding)
   end ops
 
   // TODO: Fix issue when converting ModeChanges and FreshModeChanges to extension givens

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

@@ -1112,9 +1112,7 @@ object Types {
      */
     def matches(that: Type)(using Context): Boolean = {
       record("matches")
-      val overrideCtx = if ctx.explicitNulls
-        then ctx.retractMode(Mode.SafeNulls).addMode(Mode.RelaxedOverriding)
-        else ctx
+      val overrideCtx = if ctx.explicitNulls then ctx.relaxedOverrideContext else ctx
       TypeComparer.matchesType(this, that, relaxed = !ctx.phase.erasedTypes)(using overrideCtx)
     }
 

compiler/src/dotty/tools/dotc/transform/OverridingPairs.scala

@@ -219,7 +219,7 @@ object OverridingPairs:
       // releaxed override check for explicit nulls if one of the symbols is Java defined,
       // force `Null` to be a subtype of non-primitive value types during override checking.
       val overrideCtx = if ctx.explicitNulls && (member.is(JavaDefined) || other.is(JavaDefined))
-        then ctx.retractMode(Mode.SafeNulls).addMode(Mode.RelaxedOverriding) else ctx
+        then ctx.relaxedOverrideContext else ctx
       member.name.is(DefaultGetterName) // default getters are not checked for compatibility
       || memberTp.overrides(otherTp,
             member.matchNullaryLoosely || other.matchNullaryLoosely || fallBack

compiler/src/dotty/tools/dotc/transform/ResolveSuper.scala

@@ -115,7 +115,7 @@ object ResolveSuper {
         // we use relaxed overriding check for explicit nulls if one of the symbols is Java defined.
         // This forces `Null` to be a subtype of non-primitive value types during override checking.
         val overrideCtx = if ctx.explicitNulls && (sym.is(JavaDefined) || acc.is(JavaDefined))
-          then ctx.retractMode(Mode.SafeNulls).addMode(Mode.RelaxedOverriding) else ctx
+          then ctx.relaxedOverrideContext else ctx
         if !otherTp.overrides(accTp, matchLoosely = true)(using overrideCtx) then
           report.error(IllegalSuperAccessor(base, memberName, targetName, acc, accTp, other.symbol, otherTp), base.srcPos)
       bcs = bcs.tail