compiler_types.h: Move __nocfi out of compiler-specific header

Prepare for GCC KCFI support and move the __nocfi attribute from
compiler-clang.h to compiler_types.h. This was already gated by
CONFIG_CFI_CLANG, so this remains safe for non-KCFI GCC builds.

Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250904034656.3670313-1-kees@kernel.org

Author: kees

include/linux/compiler-clang.h

@@ -96,11 +96,6 @@
 # define __noscs	__attribute__((__no_sanitize__("shadow-call-stack")))
 #endif
 
-#if __has_feature(kcfi)
-/* Disable CFI checking inside a function. */
-#define __nocfi		__attribute__((__no_sanitize__("kcfi")))
-#endif
-
 /*
  * Turn individual warnings and errors on and off locally, depending
  * on version.

include/linux/compiler_types.h

@@ -432,7 +432,9 @@ struct ftrace_likely_data {
 # define __noscs
 #endif
 
-#ifndef __nocfi
+#if defined(CONFIG_CFI_CLANG)
+# define __nocfi		__attribute__((__no_sanitize__("kcfi")))
+#else
 # define __nocfi
 #endif