Revert of Add unoptimized/optimized variants of MathFloor TF code stub

src/mips/interface-descriptors-mips.cc

Index: src/mips/interface-descriptors-mips.cc
diff --git a/src/mips/interface-descriptors-mips.cc b/src/mips/interface-descriptors-mips.cc
index 0c00833fb60fbe4cd9a38fce706e6e25597667da..0379da0ad8236d2a923b73193f82c2dfe7769dfc 100644
--- a/src/mips/interface-descriptors-mips.cc
+++ b/src/mips/interface-descriptors-mips.cc
@@ -330,25 +330,14 @@
 }
 
 
-void MathRoundVariantCallFromUnoptimizedCodeDescriptor::
-    InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
+void MathRoundVariantDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a1,  // math rounding function
       a3,  // vector slot id
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
-
-
-void MathRoundVariantCallFromOptimizedCodeDescriptor::
-    InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // math rounding function
-      a3,  // vector slot id
-      a2,  // type vector
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
 }  // namespace internal
 }  // namespace v8