PPC64: Implemented the Word64Popcnt TurboFan operator.

src/ppc/simulator-ppc.cc

Index: src/ppc/simulator-ppc.cc
diff --git a/src/ppc/simulator-ppc.cc b/src/ppc/simulator-ppc.cc
index cdce60eb5980f73ffa5015b0199a3595d454e137..88cc760d2d3efe0365708934d43f6d61beecb6ce 100644
--- a/src/ppc/simulator-ppc.cc
+++ b/src/ppc/simulator-ppc.cc
@@ -1863,6 +1863,22 @@ bool Simulator::ExecuteExt2_10bit(Instruction* instr) {
       set_register(ra, count);
       break;
     }
+#if V8_TARGET_ARCH_PPC64
+    case POPCNTD: {
+      int rs = instr->RSValue();
+      int ra = instr->RAValue();
+      uintptr_t rs_val = get_register(rs);
+      uintptr_t count = 0;
+      int n = 0;
+      uintptr_t bit = 0x8000000000000000UL;
+      for (; n < 64; n++) {
+        if (bit & rs_val) count++;
+        bit >>= 1;
+      }
+      set_register(ra, count);
+      break;
+    }
+#endif
     case SYNC: {
       // todo - simulate sync
       break;