x86/percpu: Enable named address spaces for GCC 9.1+

Enable named address spaces also for GCC 9, GCC 10 and GCC 11
releases. These compilers all produce kernel images that boot
without problems.

GCC_VERSION cutoff is arbitrary. It is primary a risk-reduction
cutoff, older compilers will be tested and enabled in linux 6.10
release.

Signed-off-by: Uros Bizjak <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: ubizjak

arch/x86/Kconfig

@@ -2433,7 +2433,7 @@ source "kernel/livepatch/Kconfig"
 endmenu
 
 config CC_HAS_NAMED_AS
-	def_bool CC_IS_GCC && GCC_VERSION >= 120100
+	def_bool CC_IS_GCC && GCC_VERSION >= 90100
 
 config CC_HAS_NAMED_AS_FIXED_ASAN
 	def_bool CC_IS_GCC && GCC_VERSION >= 130300