[compiler-rt] Adds builtins support for xros.

Author: rohit-rao

compiler-rt/cmake/builtin-config-ix.cmake

@@ -92,6 +92,8 @@ if(APPLE)
   find_darwin_sdk_dir(DARWIN_watchos_SYSROOT watchos)
   find_darwin_sdk_dir(DARWIN_tvossim_SYSROOT appletvsimulator)
   find_darwin_sdk_dir(DARWIN_tvos_SYSROOT appletvos)
+  find_darwin_sdk_dir(DARWIN_xrossim_SYSROOT xrsimulator)
+  find_darwin_sdk_dir(DARWIN_xros_SYSROOT xros)
 
   # Get supported architecture from SDKSettings.
   function(sdk_has_arch_support sdk_path os arch has_support)
@@ -162,6 +164,11 @@ if(APPLE)
       list(APPEND DARWIN_tvossim_BUILTIN_ALL_POSSIBLE_ARCHS arm64)
     endif()
   endif()
+  if(COMPILER_RT_ENABLE_XROS)
+    list(APPEND DARWIN_EMBEDDED_PLATFORMS xros)
+    set(DARWIN_xros_BUILTIN_ALL_POSSIBLE_ARCHS arm64)
+    set(DARWIN_xrossim_BUILTIN_ALL_POSSIBLE_ARCHS ${X86_64} arm64)
+  endif()
 
   set(BUILTIN_SUPPORTED_OS osx)