Bug 1885840 - Remove non-const overloads of apply and map for Maybe<T&>. r=glandium

They don't add any functionality since there is no non-const variant of ref().

Differential Revision: https://phabricator.services.mozilla.com/D204993

mfbt/Maybe.h

@@ -736,14 +736,6 @@ class Maybe<T&> {
 
   void reset() { mValue = nullptr; }
 
-  template <typename Func>
-  Maybe& apply(Func&& aFunc) {
-    if (isSome()) {
-      std::forward<Func>(aFunc)(ref());
-    }
-    return *this;
-  }
-
   template <typename Func>
   const Maybe& apply(Func&& aFunc) const {
     if (isSome()) {
@@ -752,15 +744,6 @@ class Maybe<T&> {
     return *this;
   }
 
-  template <typename Func>
-  auto map(Func&& aFunc) {
-    Maybe<decltype(std::forward<Func>(aFunc)(ref()))> val;
-    if (isSome()) {
-      val.emplace(std::forward<Func>(aFunc)(ref()));
-    }
-    return val;
-  }
-
   template <typename Func>
   auto map(Func&& aFunc) const {
     Maybe<decltype(std::forward<Func>(aFunc)(ref()))> val;