PPC: Make arguments adaptor not clobber new.target.

Port c1e7c8d9

Original commit message:
    This ensures that the ArgumentsAdaptorTrampoline does not clobber the
    new.target value, but rather passes it through to the callee unaltered.
    Note that callees do not yet use the new.target value so far.

    This is a preparatory CL to allows us passing new.target in a register
    instead of via a side-channel through the construct stub frame.

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4544
LOG=n

Review URL: https://codereview.chromium.org/1467923004

Cr-Commit-Position: refs/heads/master@{#32184}

src/ppc/builtins-ppc.cc

@@ -1428,6 +1428,7 @@ static void ArgumentAdaptorStackCheck(MacroAssembler* masm,
   //  -- r3 : actual number of arguments
   //  -- r4 : function (passed through to callee)
   //  -- r5 : expected number of arguments
+  //  -- r6 : new target (passed through to callee)
   // -----------------------------------
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
@@ -1717,11 +1718,10 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   //  -- r3 : actual number of arguments
   //  -- r4 : function (passed through to callee)
   //  -- r5 : expected number of arguments
+  //  -- r6 : new target (passed through to callee)
   // -----------------------------------
 
-  Label stack_overflow;
-  ArgumentAdaptorStackCheck(masm, &stack_overflow);
-  Label invoke, dont_adapt_arguments;
+  Label invoke, dont_adapt_arguments, stack_overflow;
 
   Label enough, too_few;
   __ LoadP(ip, FieldMemOperand(r4, JSFunction::kCodeEntryOffset));
@@ -1733,31 +1733,34 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   {  // Enough parameters: actual >= expected
     __ bind(&enough);
     EnterArgumentsAdaptorFrame(masm);
+    ArgumentAdaptorStackCheck(masm, &stack_overflow);
 
-    // Calculate copy start address into r3 and copy end address into r6.
+    // Calculate copy start address into r3 and copy end address into r7.
     // r3: actual number of arguments as a smi
     // r4: function
     // r5: expected number of arguments
+    // r6: new target (passed through to callee)
     // ip: code entry to call
     __ SmiToPtrArrayOffset(r3, r3);
     __ add(r3, r3, fp);
     // adjust for return address and receiver
     __ addi(r3, r3, Operand(2 * kPointerSize));
-    __ ShiftLeftImm(r6, r5, Operand(kPointerSizeLog2));
-    __ sub(r6, r3, r6);
+    __ ShiftLeftImm(r7, r5, Operand(kPointerSizeLog2));
+    __ sub(r7, r3, r7);
 
     // Copy the arguments (including the receiver) to the new stack frame.
     // r3: copy start address
     // r4: function
     // r5: expected number of arguments
-    // r6: copy end address
+    // r6: new target (passed through to callee)
+    // r7: copy end address
     // ip: code entry to call
 
     Label copy;
     __ bind(&copy);
     __ LoadP(r0, MemOperand(r3, 0));
     __ push(r0);
-    __ cmp(r3, r6);  // Compare before moving to next argument.
+    __ cmp(r3, r7);  // Compare before moving to next argument.
     __ subi(r3, r3, Operand(kPointerSize));
     __ bne(&copy);
 
@@ -1793,11 +1796,13 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 
     __ bind(&no_strong_error);
     EnterArgumentsAdaptorFrame(masm);
+    ArgumentAdaptorStackCheck(masm, &stack_overflow);
 
     // Calculate copy start address into r0 and copy end address is fp.
     // r3: actual number of arguments as a smi
     // r4: function
     // r5: expected number of arguments
+    // r6: new target (passed through to callee)
     // ip: code entry to call
     __ SmiToPtrArrayOffset(r3, r3);
     __ add(r3, r3, fp);
@@ -1806,6 +1811,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // r3: copy start address
     // r4: function
     // r5: expected number of arguments
+    // r6: new target (passed through to callee)
     // ip: code entry to call
     Label copy;
     __ bind(&copy);
@@ -1819,18 +1825,19 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // Fill the remaining expected arguments with undefined.
     // r4: function
     // r5: expected number of arguments
+    // r6: new target (passed through to callee)
     // ip: code entry to call
     __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
-    __ ShiftLeftImm(r6, r5, Operand(kPointerSizeLog2));
-    __ sub(r6, fp, r6);
+    __ ShiftLeftImm(r7, r5, Operand(kPointerSizeLog2));
+    __ sub(r7, fp, r7);
     // Adjust for frame.
-    __ subi(r6, r6, Operand(StandardFrameConstants::kFixedFrameSizeFromFp +
+    __ subi(r7, r7, Operand(StandardFrameConstants::kFixedFrameSizeFromFp +
                             2 * kPointerSize));
 
     Label fill;
     __ bind(&fill);
     __ push(r0);
-    __ cmp(sp, r6);
+    __ cmp(sp, r7);
     __ bne(&fill);
   }
 
@@ -1839,6 +1846,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   __ mr(r3, r5);
   // r3 : expected number of arguments
   // r4 : function (passed through to callee)
+  // r6 : new target (passed through to callee)
   __ CallJSEntry(ip);
 
   // Store offset of return address for deoptimizer.
@@ -1858,7 +1866,6 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   __ bind(&stack_overflow);
   {
     FrameScope frame(masm, StackFrame::MANUAL);
-    EnterArgumentsAdaptorFrame(masm);
     __ CallRuntime(Runtime::kThrowStackOverflow, 0);
     __ bkpt(0);
   }