PPC: Fix simulator and re-enable wasm tests.

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 8de58f31aede7b053fd265894abec6f6a8641bd1..0efa6605d58a82089bf0271a94b3f4be13aca780 100644
--- a/src/ppc/simulator-ppc.cc
+++ b/src/ppc/simulator-ppc.cc
@@ -3861,6 +3861,9 @@ void Simulator::CallInternal(byte* entry) {
   set_pc(reinterpret_cast<intptr_t>(entry));
 #endif
 
+  // Put target address in ip (for JS prologue).
+  set_register(r12, get_pc());
+
   // Put down marker for end of simulation. The simulator will stop simulation
   // when the PC reaches this value. By saving the "end simulation" value into
   // the LR the simulation stops when returning to this call point.