[libc] Fix setjmp build order. (#144917)

Fix build order issue from
#139555.

Author: lntue

libc/src/setjmp/CMakeLists.txt

@@ -1,7 +1,4 @@
 # Process architecture-specific subdirectory FIRST to avoid missing targets.
-if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
-  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
-endif()
 
 # Then process OS-specific subdirectory
 if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
@@ -14,6 +11,10 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
   )
 endif()
 
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_ARCHITECTURE})
+endif()
+
 add_entrypoint_object(
   setjmp
   ALIAS