S390: Fix popcnt64 should use lgbr for final dst.

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 d5bc55e633c73397b75d963e74a366dc08d840ef..83f6aa4fd734bed823d0b97481414e150de366f6 100644
--- a/src/s390/macro-assembler-s390.cc
+++ b/src/s390/macro-assembler-s390.cc
@@ -5324,7 +5324,7 @@ void MacroAssembler::Popcnt32(Register dst, Register src) {
   ar(dst, r0);
   ShiftRight(r0, dst, Operand(8));
   ar(dst, r0);
-  lbr(dst, dst);
+  LoadB(dst, dst);
 }
 
 #ifdef V8_TARGET_ARCH_S390X
@@ -5339,7 +5339,7 @@ void MacroAssembler::Popcnt64(Register dst, Register src) {
   AddP(dst, r0);
   ShiftRightP(r0, dst, Operand(8));
   AddP(dst, r0);
-  lbr(dst, dst);
+  LoadB(dst, dst);
 }
 #endif