[turbofan] Explicitly mark call sites as patchable.

src/compiler/arm/code-generator-arm.cc

Index: src/compiler/arm/code-generator-arm.cc
diff --git a/src/compiler/arm/code-generator-arm.cc b/src/compiler/arm/code-generator-arm.cc
index b11cdbd92c7c8476268fd02c083b42c17bfad581..762572bb87efc33fc1308292563329b5933996bf 100644
--- a/src/compiler/arm/code-generator-arm.cc
+++ b/src/compiler/arm/code-generator-arm.cc
@@ -841,10 +841,10 @@ void CodeGenerator::AssembleSwap(InstructionOperand* source,
 
 void CodeGenerator::AddNopForSmiCodeInlining() {
   // On 32-bit ARM we do not insert nops for inlined Smi code.
-  UNREACHABLE();
 }
 
 #undef __
-}
-}
-}  // namespace v8::internal::compiler
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8