NFC: Use SWIFT_APPLE_PLATFORMS and remove is_darwin_based_sdk

Author: kubamracek

stdlib/cmake/modules/AddSwiftStdlib.cmake

@@ -2,20 +2,6 @@
 include(AddSwift)
 include(SwiftSource)
 
-function(is_darwin_based_sdk sdk_name out_var)
-  if ("${sdk_name}" STREQUAL "OSX" OR
-      "${sdk_name}" STREQUAL "IOS" OR
-      "${sdk_name}" STREQUAL "IOS_SIMULATOR" OR
-      "${sdk_name}" STREQUAL "TVOS" OR
-      "${sdk_name}" STREQUAL "TVOS_SIMULATOR" OR
-      "${sdk_name}" STREQUAL "WATCHOS" OR
-      "${sdk_name}" STREQUAL "WATCHOS_SIMULATOR")
-    set(${out_var} TRUE PARENT_SCOPE)
-  else()
-    set(${out_var} FALSE PARENT_SCOPE)
-  endif()
-endfunction()
-
 function(add_dependencies_multiple_targets)
   cmake_parse_arguments(
       ADMT # prefix
@@ -63,8 +49,7 @@ function(_add_target_variant_c_compile_link_flags)
 
   set(result ${${CFLAGS_RESULT_VAR_NAME}})
 
-  is_darwin_based_sdk("${CFLAGS_SDK}" IS_DARWIN)
-  if(IS_DARWIN)
+  if("${CFLAGS_SDK}" IN_LIST SWIFT_APPLE_PLATFORMS)
     # Check if there's a specific OS deployment version needed for this invocation
     if("${CFLAGS_SDK}" STREQUAL "OSX")
       if(DEFINED maccatalyst_build_flavor)
@@ -113,7 +98,7 @@ function(_add_target_variant_c_compile_link_flags)
     endif()
   endif()
 
-  if(IS_DARWIN)
+  if("${CFLAGS_SDK}" IN_LIST SWIFT_APPLE_PLATFORMS)
     # We collate -F with the framework path to avoid unwanted deduplication
     # of options by target_compile_options -- this way no undesired
     # side effects are introduced should a new search path be added.

stdlib/cmake/modules/SwiftSource.cmake

@@ -210,8 +210,7 @@ function(_add_target_variant_swift_compile_flags
     list(APPEND result "-sdk" "${SWIFT_SDK_${sdk}_ARCH_${arch}_PATH}")
   endif()
 
-  is_darwin_based_sdk("${sdk}" IS_DARWIN)
-  if(IS_DARWIN)
+  if("${sdk}" IN_LIST SWIFT_APPLE_PLATFORMS)
     set(sdk_deployment_version "${SWIFT_SDK_${sdk}_DEPLOYMENT_VERSION}")
     get_target_triple(target target_variant "${sdk}" "${arch}"
     MACCATALYST_BUILD_FLAVOR "${VARIANT_MACCATALYST_BUILD_FLAVOR}"
@@ -237,7 +236,7 @@ function(_add_target_variant_swift_compile_flags
     list(APPEND result "-resource-dir" "${SWIFTLIB_DIR}")
   endif()
 
-  if(IS_DARWIN)
+  if("${sdk}" IN_LIST SWIFT_APPLE_PLATFORMS)
     # We collate -F with the framework path to avoid unwanted deduplication
     # of options by target_compile_options -- this way no undesired
     # side effects are introduced should a new search path be added.