[turbofan] Implemented the optional Float32RoundTiesEven operator.

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index f8c72575ff9ef76d1e47ef11ac7b2dfd4af67e56..46fff295515c61ddf20bf82f994bfef9c94410b6 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -644,6 +644,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kArm64Float64RoundTruncate:
       __ Frintz(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
+    case kArm64Float32RoundTiesEven:
+      __ Frintn(i.OutputFloat32Register(), i.InputFloat32Register(0));
+      break;
     case kArm64Float64RoundTiesEven:
       __ Frintn(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;