Revert of 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 8412c46ea0f38eab46aaa7c683c1d4e438705f0c..62e6f2a79e9cbb4e764f5b4fec6c185b35324049 100644
--- a/src/arm64/interface-descriptors-arm64.cc
+++ b/src/arm64/interface-descriptors-arm64.cc
@@ -389,25 +389,14 @@
 }
 
 
-void MathRoundVariantCallFromUnoptimizedCodeDescriptor::
-    InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
+void MathRoundVariantDescriptor::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);
-}
 }  // namespace internal
 }  // namespace v8