[gn build] Manually port d423d80

Author: aeubanks

llvm/utils/gn/secondary/libcxx/include/BUILD.gn

@@ -37,9 +37,9 @@ if (current_toolchain == default_toolchain) {
       "_LIBCPP_INSTRUMENTED_WITH_ASAN=",
       "_LIBCPP_ABI_DEFINES=",
       "_LIBCPP_HARDENING_MODE_DEFAULT=_LIBCPP_HARDENING_MODE_NONE",
-      "_LIBCPP_PSTL_CPU_BACKEND_LIBDISPATCH=",
-      "_LIBCPP_PSTL_CPU_BACKEND_SERIAL=1",
-      "_LIBCPP_PSTL_CPU_BACKEND_THREAD=",
+      "_LIBCPP_PSTL_BACKEND_LIBDISPATCH=",
+      "_LIBCPP_PSTL_BACKEND_SERIAL=1",
+      "_LIBCPP_PSTL_BACKEND_STD_THREAD=",
     ]
     if (libcxx_abi_version != 1) {
       values += [ "_LIBCPP_ABI_VERSION=$libcxx_abi_version" ]
@@ -143,18 +143,12 @@ if (current_toolchain == default_toolchain) {
       "__algorithm/pop_heap.h",
       "__algorithm/prev_permutation.h",
       "__algorithm/pstl_any_all_none_of.h",
-      "__algorithm/pstl_backend.h",
-      "__algorithm/pstl_backends/cpu_backend.h",
       "__algorithm/pstl_backends/cpu_backends/any_of.h",
-      "__algorithm/pstl_backends/cpu_backends/backend.h",
       "__algorithm/pstl_backends/cpu_backends/fill.h",
       "__algorithm/pstl_backends/cpu_backends/find_if.h",
       "__algorithm/pstl_backends/cpu_backends/for_each.h",
-      "__algorithm/pstl_backends/cpu_backends/libdispatch.h",
       "__algorithm/pstl_backends/cpu_backends/merge.h",
-      "__algorithm/pstl_backends/cpu_backends/serial.h",
       "__algorithm/pstl_backends/cpu_backends/stable_sort.h",
-      "__algorithm/pstl_backends/cpu_backends/thread.h",
       "__algorithm/pstl_backends/cpu_backends/transform.h",
       "__algorithm/pstl_backends/cpu_backends/transform_reduce.h",
       "__algorithm/pstl_copy.h",
@@ -664,6 +658,11 @@ if (current_toolchain == default_toolchain) {
       "__numeric/transform_exclusive_scan.h",
       "__numeric/transform_inclusive_scan.h",
       "__numeric/transform_reduce.h",
+      "__pstl/backends/libdispatch.h",
+      "__pstl/backends/serial.h",
+      "__pstl/backends/std_thread.h",
+      "__pstl/configuration.h",
+      "__pstl/configuration_fwd.h",
       "__pstl/cpu_algos/cpu_traits.h",
       "__random/bernoulli_distribution.h",
       "__random/binomial_distribution.h",