[turbofan] Initial support for inline allocations of arrays.

src/type-cache.h

Index: src/type-cache.h
diff --git a/src/type-cache.h b/src/type-cache.h
index 512d9b9a2648d5771b82f0e4d60810007a95762a..4fc95a3d4f83f8edeb58715fe2735626e89f74fd 100644
--- a/src/type-cache.h
+++ b/src/type-cache.h
@@ -94,6 +94,10 @@ class TypeCache final {
   Type* const kStringLengthType =
       CreateNative(CreateRange(0.0, String::kMaxLength), Type::TaggedSigned());
 
+  // When initializing arrays, we'll unfold the loop if the number of
+  // elements is known to be of this type.
+  Type* const kElementLoopUnrollType = CreateRange(0.0, 16.0);
+
 #define TYPED_ARRAY(TypeName, type_name, TYPE_NAME, ctype, size) \
   Type* const k##TypeName##Array = CreateArray(k##TypeName);
   TYPED_ARRAYS(TYPED_ARRAY)