Reland: Add unoptimized/optimized variants of MathFloor TF code stub

src/arm64/interface-descriptors-arm64.cc

Index: src/arm64/interface-descriptors-arm64.cc
diff --git a/src/arm64/interface-descriptors-arm64.cc b/src/arm64/interface-descriptors-arm64.cc
index 62e6f2a79e9cbb4e764f5b4fec6c185b35324049..8412c46ea0f38eab46aaa7c683c1d4e438705f0c 100644
--- a/src/arm64/interface-descriptors-arm64.cc
+++ b/src/arm64/interface-descriptors-arm64.cc
@@ -389,11 +389,22 @@ void ApiAccessorDescriptor::InitializePlatformSpecific(
 }
 
 
-void MathRoundVariantDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
+void MathRoundVariantCallFromUnoptimizedCodeDescriptor::
+    InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
+  Register registers[] = {
+      x1,  // math rounding function
+      x3,  // vector slot id
+  };
+  data->InitializePlatformSpecific(arraysize(registers), registers);
+}
+
+
+void MathRoundVariantCallFromOptimizedCodeDescriptor::
+    InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
   Register registers[] = {
       x1,  // math rounding function
       x3,  // vector slot id
+      x4,  // type vector
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }