[turbofan] Make new.target explicit in JSCallDescriptor.

src/ppc/macro-assembler-ppc.h

Index: src/ppc/macro-assembler-ppc.h
diff --git a/src/ppc/macro-assembler-ppc.h b/src/ppc/macro-assembler-ppc.h
index 8a8bca975106fc6fee42b14a7ec83999f2aff0e5..5e46cf571bd561650fb67e560dd396b2cc25e3ff 100644
--- a/src/ppc/macro-assembler-ppc.h
+++ b/src/ppc/macro-assembler-ppc.h
@@ -24,6 +24,7 @@ const Register kInterpreterBytecodeOffsetRegister = {Register::kCode_r15};
 const Register kInterpreterBytecodeArrayRegister = {Register::kCode_r16};
 const Register kInterpreterDispatchTableRegister = {Register::kCode_r17};
 const Register kJavaScriptCallArgCountRegister = {Register::kCode_r3};
+const Register kJavaScriptCallNewTargetRegister = {Register::kCode_r6};
 const Register kRuntimeCallFunctionRegister = {Register::kCode_r4};
 const Register kRuntimeCallArgCountRegister = {Register::kCode_r3};