[libc] Temporarily disable LTO flags for AMDGPU crt1.o

Summary:
Some recent changes seem to have introduced a bug that breaks this. Turn
it off while I triage it.

Author: jhuber6

libc/startup/gpu/CMakeLists.txt

@@ -33,8 +33,14 @@ function(add_startup_object name)
     set_target_properties(${fq_target_name}.exe PROPERTIES
       RUNTIME_OUTPUT_DIRECTORY ${LIBC_LIBRARY_DIR}
       RUNTIME_OUTPUT_NAME ${name}.o)
-    target_link_options(${fq_target_name}.exe PRIVATE
-                        "-r" "-nostdlib" "-flto" "-Wl,--lto-emit-llvm")
+    # FIXME: A bug in the AMDGPU LTO pass is incorrectly removing the kernels.
+    if(LIBC_TARGET_ARCHITECTURE_IS_NVPTX)
+      target_link_options(${fq_target_name}.exe PRIVATE
+                          "-r" "-nostdlib" "-flto" "-Wl,--lto-emit-llvm")
+    else()
+      target_link_options(${fq_target_name}.exe PRIVATE
+                          "-r" "-nostdlib" "-Wl,--lto-emit-llvm")
+    endif()
   endif()
 endfunction()