Cut FOR_EACH_ENUMERATE

Summary: [Folly] Cut the `FOR_EACH_ENUMERATE` macro, which may be replaced by a combination of range-for, `ranges::view::enumerate`, and structured bindings.

Reviewed By: markisaa

Differential Revision: D21813019

fbshipit-source-id: fc9ac09a4e2f72f1433d0a518f03d5cd69a59c55

.clang-format

@@ -42,7 +42,7 @@ ContinuationIndentWidth: 4
 Cpp11BracedListStyle: true
 DerivePointerAlignment: false
 DisableFormat:   false
-ForEachMacros:   [ FOR_EACH, FOR_EACH_ENUMERATE, FOR_EACH_KV, FOR_EACH_R, FOR_EACH_RANGE, ]
+ForEachMacros:   [ FOR_EACH, FOR_EACH_KV, FOR_EACH_R, FOR_EACH_RANGE, ]
 IncludeCategories:
   - Regex:           '^<.*\.h(pp)?>'
     Priority:        1