target/s390x: Fix LCBB overwriting the top 32 bits

LCBB is supposed to overwrite only the bottom 32 bits, but QEMU
erroneously overwrites the entire register.

Fixes: 6d93033 ("s390x/tcg: Implement LOAD COUNT TO BLOCK BOUNDARY")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230526181240.1425579-2-iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit 079181b)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target/s390x/tcg/insn-data.h.inc

@@ -486,7 +486,7 @@
     F(0xb343, LCXBR,   RRE,   Z,   x2h, x2l, new_P, x1_P, negf128, f128, IF_BFP)
     F(0xb373, LCDFR,   RRE,   FPSSH, 0, f2, new, f1, negf64, 0, IF_AFP1 | IF_AFP2)
 /* LOAD COUNT TO BLOCK BOUNDARY */
-    C(0xe727, LCBB,    RXE,   V,   la2, 0, r1, 0, lcbb, 0)
+    C(0xe727, LCBB,    RXE,   V,   la2, 0, new, r1_32, lcbb, 0)
 /* LOAD HALFWORD */
     C(0xb927, LHR,     RRE,   EI,  0, r2_16s, 0, r1_32, mov2, 0)
     C(0xb907, LGHR,    RRE,   EI,  0, r2_16s, 0, r1, mov2, 0)