PPC: [debugger] do not restart frames that reference new.target for liveedit.c

Port 6fca8702

R=yangguo@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1497793002

Cr-Commit-Position: refs/heads/master@{#32589}

src/debug/ppc/debug-ppc.cc

@@ -138,6 +138,9 @@ void DebugCodegen::GenerateFrameDropperLiveEdit(MacroAssembler* masm) {
   // Load context from the function.
   __ LoadP(cp, FieldMemOperand(r4, JSFunction::kContextOffset));
 
+  // Clear new.target as a safety measure.
+  __ LoadRoot(r6, Heap::kUndefinedValueRootIndex);
+
   // Get function code.
   __ LoadP(ip, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
   __ LoadP(ip, FieldMemOperand(ip, SharedFunctionInfo::kCodeOffset));