[Compiler] Move static FinishCode function into CodeGenerator.

src/compiler/s390/code-generator-s390.cc

Index: src/compiler/s390/code-generator-s390.cc
diff --git a/src/compiler/s390/code-generator-s390.cc b/src/compiler/s390/code-generator-s390.cc
index 916323b22c74066b7445fc0beda43ec9de0f55a2..d64b9985a4ffef3864d741acb2e0338f3f963f49 100644
--- a/src/compiler/s390/code-generator-s390.cc
+++ b/src/compiler/s390/code-generator-s390.cc
@@ -2702,6 +2702,8 @@ void CodeGenerator::AssembleReturn(InstructionOperand* pop) {
   __ Ret();
 }
 
+void CodeGenerator::FinishCode() {}
+
 void CodeGenerator::AssembleMove(InstructionOperand* source,
                                  InstructionOperand* destination) {
   S390OperandConverter g(this, nullptr);