[turbofan] Cleanup duplicated/unused code in InstructionSelector.

src/zone-containers.h

Index: src/zone-containers.h
diff --git a/src/zone-containers.h b/src/zone-containers.h
index b0ff7b6cf1bc68297ded6eae7e4bb76f322b18a9..de635fde05dda6ef0d4058c63552809a86a0469d 100644
--- a/src/zone-containers.h
+++ b/src/zone-containers.h
@@ -27,12 +27,12 @@ class ZoneVector : public std::vector<T, zone_allocator<T>> {
 
   // Constructs a new vector and fills it with {size} elements, each
   // constructed via the default constructor.
-  ZoneVector(int size, Zone* zone)
+  ZoneVector(size_t size, Zone* zone)
       : std::vector<T, zone_allocator<T>>(size, T(), zone_allocator<T>(zone)) {}
 
   // Constructs a new vector and fills it with {size} elements, each
   // having the value {def}.
-  ZoneVector(int size, T def, Zone* zone)
+  ZoneVector(size_t size, T def, Zone* zone)
       : std::vector<T, zone_allocator<T>>(size, def, zone_allocator<T>(zone)) {}
 };