Extend TF test coverage to unsupported targets.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index 5a513a54c16cfc1397431ef18457f80a28feae67..cbe5ae19341d68b19787d3aee1a1530f4c528764 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -9,6 +9,8 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+#if V8_TURBOFAN_TARGET
+
 enum ImmediateMode {
   kArithimeticImm,  // 12 bit unsigned immediate shifted left 0 or 12 bits
   kShift32Imm,      // 0 - 31
@@ -658,6 +660,8 @@ void InstructionSelector::VisitCall(Node* call, BasicBlock* continuation,
   }
 }
 
+#endif  // V8_TURBOFAN_TARGET
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8