loongarch: Use ASM_REACHABLE

annotate_reachable() is unreliable since the compiler is free to place
random code inbetween two consecutive asm() statements.

This removes the last and only annotate_reachable() user.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094312.133437051@infradead.org

arch/loongarch/include/asm/bug.h

@@ -4,6 +4,7 @@
 
 #include <asm/break.h>
 #include <linux/stringify.h>
+#include <linux/objtool.h>
 
 #ifndef CONFIG_DEBUG_BUGVERBOSE
 #define _BUGVERBOSE_LOCATION(file, line)
@@ -33,25 +34,25 @@
 
 #define ASM_BUG_FLAGS(flags)					\
 	__BUG_ENTRY(flags)					\
-	break		BRK_BUG
+	break		BRK_BUG;
 
 #define ASM_BUG()	ASM_BUG_FLAGS(0)
 
-#define __BUG_FLAGS(flags)					\
-	asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags)));
+#define __BUG_FLAGS(flags, extra)					\
+	asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags))		\
+			     extra);
 
 #define __WARN_FLAGS(flags)					\
 do {								\
 	instrumentation_begin();				\
-	__BUG_FLAGS(BUGFLAG_WARNING|(flags));			\
-	annotate_reachable();					\
+	__BUG_FLAGS(BUGFLAG_WARNING|(flags), ASM_REACHABLE);	\
 	instrumentation_end();					\
 } while (0)
 
 #define BUG()							\
 do {								\
 	instrumentation_begin();				\
-	__BUG_FLAGS(0);						\
+	__BUG_FLAGS(0, "");					\
 	unreachable();						\
 } while (0)