s390: preserve src register in MovIntToFloat

src/s390/macro-assembler-s390.cc

Index: src/s390/macro-assembler-s390.cc
diff --git a/src/s390/macro-assembler-s390.cc b/src/s390/macro-assembler-s390.cc
index 78622d7d1d7b469eaff6d1c98f5558ffc8f74b26..48f99549186f8208a96736e72007bee9c9b39933 100644
--- a/src/s390/macro-assembler-s390.cc
+++ b/src/s390/macro-assembler-s390.cc
@@ -3831,8 +3831,8 @@ void MacroAssembler::SubP(Register dst, const MemOperand& opnd) {
 }
 
 void MacroAssembler::MovIntToFloat(DoubleRegister dst, Register src) {
-  sllg(src, src, Operand(32));
-  ldgr(dst, src);
+  sllg(r0, src, Operand(32));
+  ldgr(dst, r0);
 }
 
 void MacroAssembler::MovFloatToInt(Register dst, DoubleRegister src) {