SwiftConfigureSDK.cmake: support freebsd-arm64

Author: MaxDesiatov

cmake/modules/SwiftConfigureSDK.cmake

@@ -378,7 +378,7 @@ macro(configure_sdk_unix name architectures)
           message(FATAL_ERROR "unknown arch for ${prefix}: ${arch}")
         endif()
       elseif("${prefix}" STREQUAL "FREEBSD")
-        if(NOT arch STREQUAL x86_64)
+        if(NOT arch MATCHES "(arm64|x86_64)")
           message(FATAL_ERROR "unsupported arch for FreeBSD: ${arch}")
         endif()
 
@@ -389,7 +389,7 @@ macro(configure_sdk_unix name architectures)
         string(REGEX REPLACE "[-].*" "" freebsd_system_version ${CMAKE_SYSTEM_VERSION})
         message(STATUS "FreeBSD Version: ${freebsd_system_version}")
 
-        set(SWIFT_SDK_FREEBSD_ARCH_x86_64_TRIPLE "x86_64-unknown-freebsd${freebsd_system_version}")
+        set(SWIFT_SDK_FREEBSD_ARCH_${arch}_TRIPLE "${arch}-unknown-freebsd${freebsd_system_version}")
       elseif("${prefix}" STREQUAL "OPENBSD")
         if(NOT arch STREQUAL amd64)
           message(FATAL_ERROR "unsupported arch for OpenBSD: ${arch}")