KVM: selftests: Tell the compiler that code after TEST_FAIL() is unreachable

Add __builtin_unreachable() to TEST_FAIL() so that the compiler knows
that any code after a TEST_FAIL() is unreachable.
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220929181207.2281449-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/include/test_util.h

@@ -63,8 +63,10 @@ void test_assert(bool exp, const char *exp_str,
 		    #a, #b, #a, (unsigned long) __a, #b, (unsigned long) __b); \
 } while (0)
 
-#define TEST_FAIL(fmt, ...) \
-	TEST_ASSERT(false, fmt, ##__VA_ARGS__)
+#define TEST_FAIL(fmt, ...) do { \
+	TEST_ASSERT(false, fmt, ##__VA_ARGS__); \
+	__builtin_unreachable(); \
+} while (0)
 
 size_t parse_size(const char *size);