PPC/s390: make target reg correct and remove unnecessary instr

R=joransiu@ca.ibm.com

Change-Id: I441427d7b769c448b1355956b16a4e7f105b149d
Reviewed-on: https://chromium-review.googlesource.com/952022Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#51777}

src/builtins/ppc/builtins-ppc.cc

@@ -823,7 +823,6 @@ static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
     static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
     __ addi(r5, optimized_code_entry,
             Operand(Code::kHeaderSize - kHeapObjectTag));
-    __ mr(ip, r5);
     __ Jump(r5);
 
     // Optimized code slot contains deoptimized code, evict it and re-enter the

src/s390/macro-assembler-s390.cc

@@ -161,7 +161,7 @@ void TurboAssembler::Call(Register target) {
 }
 
 void MacroAssembler::CallJSEntry(Register target) {
-  DCHECK(target == ip);
+  DCHECK(target == r4);
   Call(target);
 }