[libc++] Fixes the Clang modular build.

[Mordante]

Summary

The patch
430b397f6715d4d2f2569716c93fcd6292ace3dc ("[libc++] Granularize <type_traits> includes in <iterator>") missed some exports in the modulemap with became apparent in the reverting commit 12cb1cb3720d.

This fixes the issue by updating the modulemap. Note that the Clang ICE is not fixed by this change.

[Mordante]

libcxx/include/module.modulemap.in

1436

Note this looks wrong from libc++'s perspective. When this "solves" the issue we need to investigate why it fixes it; I think the export belongs to a different header.

[Mordante]

Fix CI run instead of libc++.

[Mordante]

Rebased and improve fixes.

[Mordante]

Finalized patch.

[Mordante]

Removes uninteded include.

[Mordante]

Undo CI changes.

[Mordante]

https://buildkite.com/llvm-project/libcxx-ci/builds/18148 shows this patch fixes the Clang modular build.

libcxx/include/module.modulemap.in

module __concepts {
       module common_reference_with      { private header "__concepts/common_reference_with.h" }
       module common_with                { private header "__concepts/common_with.h" }
       module constructible              { private header "__concepts/constructible.h" }
       module convertible_to             { private header "__concepts/convertible_to.h" }
       module copyable                   { private header "__concepts/copyable.h" }
       module derived_from               { private header "__concepts/derived_from.h" }
       module destructible               { private header "__concepts/destructible.h" }
       module different_from             { private header "__concepts/different_from.h" }
-      module equality_comparable        { private header "__concepts/equality_comparable.h" }
+      module equality_comparable {
+        private header "__concepts/equality_comparable.h"
+        export type_traits.common_reference
+      }
       module invocable                  { private header "__concepts/invocable.h" }
       module movable                    { private header "__concepts/movable.h" }
       module predicate                  { private header "__concepts/predicate.h" }
       module regular                    { private header "__concepts/regular.h" }
       module relation                   { private header "__concepts/relation.h" }
-      module same_as                    { private header "__concepts/same_as.h" }
+      module same_as {
+        private header "__concepts/same_as.h"
+        export type_traits.is_same
+      }
       module semiregular                { private header "__concepts/semiregular.h" }
       module swappable                  { private header "__concepts/swappable.h" }
       module totally_ordered            { private header "__concepts/totally_ordered.h" }
     }
   }
   module condition_variable {
     header "condition_variable"
     export *
module iterator {
     export *
 
     module __iterator {
       module access                { private header "__iterator/access.h" }
       module advance               { private header "__iterator/advance.h" }
       module back_insert_iterator  { private header "__iterator/back_insert_iterator.h" }
       module bounded_iter          { private header "__iterator/bounded_iter.h" }
       module common_iterator       { private header "__iterator/common_iterator.h" }
-      module concepts              { private header "__iterator/concepts.h" }
+      module concepts {
+        private header "__iterator/concepts.h"
+        export concepts.equality_comparable
+        export type_traits.common_reference
+      }
       module counted_iterator      { private header "__iterator/counted_iterator.h" }
       module data                  { private header "__iterator/data.h" }
       module default_sentinel      { private header "__iterator/default_sentinel.h" }
       module distance              { private header "__iterator/distance.h" }
       module empty                 { private header "__iterator/empty.h" }
       module erase_if_container    { private header "__iterator/erase_if_container.h" }
       module front_insert_iterator { private header "__iterator/front_insert_iterator.h" }
       module incrementable_traits  { private header "__iterator/incrementable_traits.h" }
module type_traits {
     module dependent_type                      { private header "__type_traits/dependent_type.h" }
     module disjunction                         { private header "__type_traits/disjunction.h" }
     module enable_if                           { private header "__type_traits/enable_if.h" }
     module extent                              { private header "__type_traits/extent.h" }
     module has_unique_object_representation    { private header "__type_traits/has_unique_object_representation.h" }
     module has_virtual_destructor              { private header "__type_traits/has_virtual_destructor.h" }
     module integral_constant                   { private header "__type_traits/integral_constant.h" }
     module is_abstract                         { private header "__type_traits/is_abstract.h" }
     module is_aggregate                        { private header "__type_traits/is_aggregate.h" }
     module is_allocator                        { private header "__type_traits/is_allocator.h" }
     module is_always_bitcastable               { private header "__type_traits/is_always_bitcastable.h" }
     module is_arithmetic {
       private header "__type_traits/is_arithmetic.h"
       export integral_constant
     }
     module is_array                            {
       private header "__type_traits/is_array.h"