Replace TARGET_WORDS_BIGENDIAN

Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/target/ppc/gdbstub.c b/target/ppc/gdbstub.c
index 105c2f7..1252429 100644
--- a/target/ppc/gdbstub.c
+++ b/target/ppc/gdbstub.c
@@ -87,9 +87,9 @@
 /*
  * We need to present the registers to gdb in the "current" memory
  * ordering.  For user-only mode we get this for free;
- * TARGET_WORDS_BIGENDIAN is set to the proper ordering for the
+ * TARGET_BIG_ENDIAN is set to the proper ordering for the
  * binary, and cannot be changed.  For system mode,
- * TARGET_WORDS_BIGENDIAN is always set, and we must check the current
+ * TARGET_BIG_ENDIAN is always set, and we must check the current
  * mode of the chip to see if we're running in little-endian.
  */
 void ppc_maybe_bswap_register(CPUPPCState *env, uint8_t *mem_buf, int len)