Support for this construct was added in 2.22 only. Avoid the need to
introduce logic to probe for linker script capabilities by (ab)using the
probe for a command line option having appeared at about the same time.

Fixes: 4b7fd8153ddf ("x86: fold sections in final binaries")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
Obviously this doesn't take care of old LLVM ld yet, if any care is
needed there in the first place.

--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -70,6 +70,11 @@ ifeq ($(CONFIG_UBSAN),y)
 $(call cc-option-add,CFLAGS_UBSAN,CC,-fno-sanitize=alignment)
 endif
 
+# While not much better than going by raw GNU ld version, utilize that the
+# feature we're after has appeared in the same release as the
+# --print-output-format command line option.
+AFLAGS-$(call ld-option,--print-output-format) += -DHAVE_LD_SORT_BY_INIT_PRIORITY
+
 ifneq ($(CONFIG_PV_SHIM_EXCLUSIVE),y)
 
 efi-check := arch/x86/efi/check
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -30,6 +30,10 @@ ENTRY(start_pa)
 # define SECTION_ALIGN PAGE_SIZE
 #endif
 
+#ifndef HAVE_LD_SORT_BY_INIT_PRIORITY
+# define SORT_BY_INIT_PRIORITY SORT
+#endif
+
 OUTPUT_FORMAT(FORMAT, FORMAT, FORMAT)
 
 OUTPUT_ARCH(i386:x86-64)