[libc++] Fix CI on release/16.x

This patch is aimed directly at release/16.x -- it ensures that we
can run the CI successfully on the release branch. It's a collection
of changes that were made on main and not backported to release/16.x
because the CI had been failing since we created the branch.

Differential Revision: https://reviews.llvm.org/D147065

Author: ldionne

libcxx/test/libcxx/assertions/headers_declare_verbose_abort.sh.cpp

@@ -663,7 +663,7 @@ int main(int, char**) { return 0; }
 #endif
 
 // RUN: %{build} -DTEST_123
-#if defined(TEST_123) && __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if defined(TEST_123) && __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
     using HandlerType = decltype(std::__libcpp_verbose_abort);
 #endif

libcxx/test/libcxx/clang_tidy.sh.cpp

@@ -217,7 +217,7 @@ END-SCRIPT
 #if __cplusplus >= 201103L
 #   include <experimental/algorithm>
 #endif
-#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L

libcxx/test/libcxx/double_include.sh.cpp

@@ -218,7 +218,7 @@ END-SCRIPT
 #if __cplusplus >= 201103L
 #   include <experimental/algorithm>
 #endif
-#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L

libcxx/test/libcxx/min_max_macros.compile.pass.cpp

@@ -341,7 +341,7 @@ TEST_MACROS();
 #   include <experimental/algorithm>
 TEST_MACROS();
 #endif
-#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 TEST_MACROS();
 #endif

libcxx/test/libcxx/modules_include.sh.cpp

@@ -544,7 +544,7 @@ END-SCRIPT
 #include <experimental/algorithm>
 #endif
 // RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fmodules-cache-path=%t -fsyntax-only -DTEST_123
-#if defined(TEST_123) && __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if defined(TEST_123) && __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #include <experimental/coroutine>
 #endif
 // RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fmodules-cache-path=%t -fsyntax-only -DTEST_124

libcxx/test/libcxx/nasty_macros.compile.pass.cpp

@@ -342,7 +342,7 @@ END-SCRIPT
 #if __cplusplus >= 201103L
 #   include <experimental/algorithm>
 #endif
-#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L

libcxx/test/libcxx/no_assert_include.compile.pass.cpp

@@ -215,7 +215,7 @@ END-SCRIPT
 #if __cplusplus >= 201103L
 #   include <experimental/algorithm>
 #endif
-#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 202002L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L

libcxx/test/libcxx/ranges/range.adaptors/range.join/segmented_iterator.compile.pass.cpp

@@ -7,8 +7,10 @@
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 #include <ranges>
+#include <utility>
 #include <vector>
 
 using JoinView = decltype(std::views::join(std::declval<std::vector<std::vector<int>>&>()));

libcxx/test/std/ranges/iterator_robust_against_adl.compile.pass.cpp

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: !c++experimental
 
 // ADL call with nested iterators of views should not look up base's view's
 // namespace

libcxx/utils/ci/buildkite-pipeline.yml

@@ -36,7 +36,9 @@ steps:
     artifact_paths:
       - "**/clang-format.patch"
     env:
-        GIT_CLANG_FORMAT: "/usr/bin/git-clang-format-${LLVM_STABLE_VERSION}"
+        GIT_CLANG_FORMAT: "/usr/bin/git-clang-format-${LLVM_STABLE_VERSION} --binary clang-format-${LLVM_STABLE_VERSION}"
+        CC: "clang-${LLVM_HEAD_VERSION}"
+        CXX: "clang++-${LLVM_HEAD_VERSION}"
     agents:
       queue: "libcxx-builders"
       os: "linux"
@@ -50,6 +52,9 @@ steps:
 
   - label: "Generated output"
     command: "libcxx/utils/ci/run-buildbot check-generated-output"
+    env:
+      CC: "clang-${LLVM_HEAD_VERSION}"
+      CXX: "clang++-${LLVM_HEAD_VERSION}"
     artifact_paths:
       - "**/generated_output.patch"
       - "**/generated_output.status"
@@ -64,6 +69,9 @@ steps:
 
   - label: "Documentation"
     command: "libcxx/utils/ci/run-buildbot documentation"
+    env:
+      CC: "clang-${LLVM_HEAD_VERSION}"
+      CXX: "clang++-${LLVM_HEAD_VERSION}"
     artifact_paths:
       - "**/test-results.xml"
     agents: