tcg: Add qemu_ld_st_i32/64

Step two in the transition, adding the new ldst opcodes.  Keep the old
opcodes around until all backends support the new opcodes.

Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index d32d7ef..fa7d966 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -130,6 +130,8 @@
 #define TCG_TARGET_HAS_mulsh_i64        0
 #endif
 
+#define TCG_TARGET_HAS_new_ldst         0
+
 #define TCG_TARGET_deposit_i32_valid(ofs, len) \
     (((ofs) == 0 && (len) == 8) || ((ofs) == 8 && (len) == 8) || \
      ((ofs) == 0 && (len) == 16))