PPC/s390: [crankshaft] Refactor kAllowUndefinedAsNaN to kTruncatingToNumber.

src/crankshaft/s390/lithium-codegen-s390.cc

Index: src/crankshaft/s390/lithium-codegen-s390.cc
diff --git a/src/crankshaft/s390/lithium-codegen-s390.cc b/src/crankshaft/s390/lithium-codegen-s390.cc
index ccb2024b94f6bc143658b27ae0b08ee252b409a8..1acaf670bdb997a788a3d95a7bf9a1be10b11b65 100644
--- a/src/crankshaft/s390/lithium-codegen-s390.cc
+++ b/src/crankshaft/s390/lithium-codegen-s390.cc
@@ -4655,8 +4655,7 @@ void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
 void LCodeGen::EmitNumberUntagD(LNumberUntagD* instr, Register input_reg,
                                 DoubleRegister result_reg,
                                 NumberUntagDMode mode) {
-  bool can_convert_undefined_to_nan =
-      instr->hydrogen()->can_convert_undefined_to_nan();
+  bool can_convert_undefined_to_nan = instr->truncating();
   bool deoptimize_on_minus_zero = instr->hydrogen()->deoptimize_on_minus_zero();
 
   Register scratch = scratch0();