[regexp] Remove unused code

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 bf668036c4632d00b77319f92c8d6c81614a0ad9..30717916c34bd6a27ff9787ba9064294e5bc2cf4 100644
--- a/src/arm64/interface-descriptors-arm64.cc
+++ b/src/arm64/interface-descriptors-arm64.cc
@@ -226,16 +226,6 @@ void ConstructTrampolineDescriptor::InitializePlatformSpecific(
 }
 
 
-void RegExpConstructResultDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x2: length
-  // x1: index (of last match)
-  // x0: string
-  Register registers[] = {x2, x1, x0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-
 void TransitionElementsKindDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // x0: value (js_array)