[turbofan] Hook up the shift code stubs with TurboFan.

src/compiler/mips64/code-generator-mips64.cc

Index: src/compiler/mips64/code-generator-mips64.cc
diff --git a/src/compiler/mips64/code-generator-mips64.cc b/src/compiler/mips64/code-generator-mips64.cc
index 1cd51a1ccd8df145a9f102f7488d3b02229d4593..cce4ef8162cf5599ded4822e3109387d212ec80c 100644
--- a/src/compiler/mips64/code-generator-mips64.cc
+++ b/src/compiler/mips64/code-generator-mips64.cc
@@ -2204,13 +2204,6 @@ void CodeGenerator::AssembleJumpTable(Label** targets, size_t target_count) {
 }
 
 
-void CodeGenerator::AddNopForSmiCodeInlining() {
-  // Unused on 32-bit ARM. Still exists on 64-bit arm.
-  // TODO(plind): Unclear when this is called now. Understand, fix if needed.
-  __ nop();  // Maybe PROPERTY_ACCESS_INLINED?
-}
-
-
 void CodeGenerator::EnsureSpaceForLazyDeopt() {
   if (!info()->ShouldEnsureSpaceForLazyDeopt()) {
     return;