add missing FOLLY_ALWAYS_INLINE to F14Map erase

Summary:
F14Map::erase(it) returns ++it for compatibility, but it
is often discarded. erase(const_iterator) was marked always-inline to
enable the computation of the return value to be optimized away, but the
annotation was missing from erase(iterator).  This also adds always-inline
annotations to a couple more methods that participate in the optimization,
but they are very good candidates for inlining regardless.

Reviewed By: yfeldblum

Differential Revision: D14854278

fbshipit-source-id: ad686b2dc8996b6a7c7038653a7c9ea1567e554d

folly/container/F14Map.h

@@ -688,7 +688,7 @@ class F14BasicMap {
 
   // This form avoids ambiguity when key_type has a templated constructor
   // that accepts const_iterator
-  iterator erase(iterator pos) {
+  FOLLY_ALWAYS_INLINE iterator erase(iterator pos) {
     auto itemPos = table_.unwrapIter(pos);
     table_.eraseIter(itemPos);
     itemPos.advanceLikelyDead();

folly/container/detail/F14Policy.h

@@ -641,7 +641,7 @@ class ValueContainerPolicy : public BasePolicy<
 
   //////// F14BasicMap/Set policy
 
-  Iter makeIter(ItemIter const& underlying) const {
+  FOLLY_ALWAYS_INLINE Iter makeIter(ItemIter const& underlying) const {
     return Iter{underlying};
   }
   ConstIter makeConstIter(ItemIter const& underlying) const {
@@ -876,7 +876,7 @@ class NodeContainerPolicy
 
   //////// F14BasicMap/Set policy
 
-  Iter makeIter(ItemIter const& underlying) const {
+  FOLLY_ALWAYS_INLINE Iter makeIter(ItemIter const& underlying) const {
     return Iter{underlying};
   }
   ConstIter makeConstIter(ItemIter const& underlying) const {