kselftest/arm64: Use the tools/include compiler.h rather than our own

The BTI test program started life as standalone programs outside the
kselftest suite so provided it's own compiler.h. Now that we have updated
the tools/include compiler.h to have all the definitions that we are using
and the arm64 selftsets pull in tools/includes let's drop our custom
version.

__unreachable() is named unreachable() there requiring an update in the
code.

Signed-off-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: broonie

tools/testing/selftests/arm64/bti/compiler.h

@@ -8,12 +8,10 @@
 
 #include <asm/unistd.h>
 
-#include "compiler.h"
-
 void __noreturn exit(int n)
 {
 	syscall(__NR_exit, n);
-	__unreachable();
+	unreachable();
 }
 
 ssize_t write(int fd, const void *buf, size_t size)

tools/testing/selftests/arm64/bti/system.c

@@ -14,12 +14,12 @@ typedef __kernel_size_t size_t;
 typedef __kernel_ssize_t ssize_t;
 
 #include <linux/errno.h>
+#include <linux/compiler.h>
+
 #include <asm/hwcap.h>
 #include <asm/ptrace.h>
 #include <asm/unistd.h>
 
-#include "compiler.h"
-
 long syscall(int nr, ...);
 
 void __noreturn exit(int n);

tools/testing/selftests/arm64/bti/system.h

@@ -17,7 +17,6 @@
 typedef struct ucontext ucontext_t;
 
 #include "btitest.h"
-#include "compiler.h"
 #include "signal.h"
 
 #define EXPECTED_TESTS 18