PPC: Allowing PPC simulator access to dynamic number of parameters

Previously we allowed for only one extra parameter on the stack,
this CL makes it dynamic based on the kArgCount value.

Change-Id: I18cd74d0cc0ecba6fb75dcee991a0e907d423d6a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1755411Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Reviewed-by: Milad Farazmand <miladfar@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#63215}

src/execution/ppc/simulator-ppc.cc

@@ -984,7 +984,9 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       }
       intptr_t* stack_pointer = reinterpret_cast<intptr_t*>(get_register(sp));
       // Remaining argument on stack
-      arg[kRegisterArgCount] = stack_pointer[kStackFrameExtraParamSlot];
+      for (int i = kRegisterArgCount, j = 0; i < kArgCount; i++, j++) {
+        arg[i] = stack_pointer[kStackFrameExtraParamSlot + j];
+      }
       STATIC_ASSERT(kArgCount == kRegisterArgCount + 2);
       STATIC_ASSERT(kMaxCParameters == kArgCount);
       bool fp_call =