PPC/s390: [Atomics] Make Atomics.exchange a builtin using TF

src/compiler/s390/instruction-selector-s390.cc

Index: src/compiler/s390/instruction-selector-s390.cc
diff --git a/src/compiler/s390/instruction-selector-s390.cc b/src/compiler/s390/instruction-selector-s390.cc
index 3a27f191af66958a02e4c349c402d766da406f92..2142d68b7fd2cff292f7f4ecb2c05944cedd690d 100644
--- a/src/compiler/s390/instruction-selector-s390.cc
+++ b/src/compiler/s390/instruction-selector-s390.cc
@@ -2517,6 +2517,8 @@ void InstructionSelector::VisitAtomicStore(Node* node) {
        inputs);
 }
 
+void InstructionSelector::VisitAtomicExchange(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {