bpf: Support can_loop/cond_break on big endian

Add big endian support for can_loop/cond_break macros.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240613013815.953-4-alexei.starovoitov@gmail.com

tools/testing/selftests/bpf/bpf_experimental.h

@@ -351,6 +351,7 @@ l_true:												\
 	l_continue:;					\
 	})
 #else
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define can_loop					\
 	({ __label__ l_break, l_continue;		\
 	bool ret = true;				\
@@ -376,6 +377,33 @@ l_true:												\
 	l_break: break;					\
 	l_continue:;					\
 	})
+#else
+#define can_loop					\
+	({ __label__ l_break, l_continue;		\
+	bool ret = true;				\
+	asm volatile goto("1:.byte 0xe5;		\
+		      .byte 0;				\
+		      .long (((%l[l_break] - 1b - 8) / 8) & 0xffff) << 16;	\
+		      .short 0"				\
+		      :::: l_break);			\
+	goto l_continue;				\
+	l_break: ret = false;				\
+	l_continue:;					\
+	ret;						\
+	})
+
+#define cond_break					\
+	({ __label__ l_break, l_continue;		\
+	asm volatile goto("1:.byte 0xe5;		\
+		      .byte 0;				\
+		      .long (((%l[l_break] - 1b - 8) / 8) & 0xffff) << 16;	\
+		      .short 0"				\
+		      :::: l_break);			\
+	goto l_continue;				\
+	l_break: break;					\
+	l_continue:;					\
+	})
+#endif
 #endif
 
 #ifndef bpf_nop_mov