PPC/s390: Fix to builtin function

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2697713006
Cr-Commit-Position: refs/heads/master@{#43227}

src/builtins/ppc/builtins-ppc.cc

@@ -640,10 +640,12 @@ void Generate_JSConstructStubHelper(MacroAssembler* masm, bool is_api_function,
     // r3: number of arguments
     // r4: constructor function
     // r6: new target
-
-    ParameterCount actual(r3);
-    __ InvokeFunction(r4, r6, actual, CALL_FUNCTION,
-                      CheckDebugStepCallWrapper());
+    {
+      ConstantPoolUnavailableScope constant_pool_unavailable(masm);
+      ParameterCount actual(r3);
+      __ InvokeFunction(r4, r6, actual, CALL_FUNCTION,
+                        CheckDebugStepCallWrapper());
+    }
 
     // Store offset of return address for deoptimizer.
     if (create_implicit_receiver && !is_api_function) {

src/builtins/s390/builtins-s390.cc

@@ -736,7 +736,7 @@ void Generate_JSConstructStubHelper(MacroAssembler* masm, bool is_api_function,
     // frame description in place of the receiver by the optimizing compiler.
     __ la(r5, MemOperand(fp, StandardFrameConstants::kCallerSPOffset));
     __ ShiftLeftP(ip, r2, Operand(kPointerSizeLog2));
-    __ LoadP(r5, MemOperand(r2, ip));
+    __ LoadP(r5, MemOperand(r5, ip));
 
     // Continue with constructor function invocation.
     __ b(&post_instantiation_deopt_entry);