Compilation: Synchronize some libcxx CXXFLAGS with upstream.

Author: alexrp

src/Compilation.zig

@@ -5382,15 +5382,15 @@ pub fn addCCArgs(
             try argv.append("-D_LIBCPP_HAS_MUSL_LIBC");
         }
         try argv.append("-D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS");
-        try argv.append("-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS");
         try argv.append("-D_LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS");
+        try argv.append("-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS");
 
         if (!comp.config.any_non_single_threaded) {
             try argv.append("-D_LIBCPP_HAS_NO_THREADS");
         }
 
         // See the comment in libcxx.zig for more details about this.
-        try argv.append("-D_LIBCPP_PSTL_CPU_BACKEND_SERIAL");
+        try argv.append("-D_LIBCPP_PSTL_BACKEND_SERIAL");
 
         try argv.append(try std.fmt.allocPrint(arena, "-D_LIBCPP_ABI_VERSION={d}", .{
             @intFromEnum(comp.libcxx_abi_version),