Remove unused external typed data factories.

runtime/vm/os.h

Index: runtime/vm/os.h
diff --git a/runtime/vm/os.h b/runtime/vm/os.h
index 3b9ac0d090dc6a1e7d1f1f8596ad0debb643af71..c36c8ed11a1c4431ccdc244c60946e735c71ac2b 100644
--- a/runtime/vm/os.h
+++ b/runtime/vm/os.h
@@ -64,23 +64,6 @@ class OS {
   // NOTE: This function will return -1 on OSs that are not supported.
   static int64_t GetCurrentThreadCPUMicros();
 
-  // Returns a cleared aligned array of type T with n entries.
-  // Alignment must be >= 16 and a power of two.
-  template<typename T>
-  static T* AllocateAlignedArray(intptr_t n, intptr_t alignment) {
-    T* result = reinterpret_cast<T*>(OS::AlignedAllocate(n * sizeof(*result),
-                                                         alignment));
-    memset(result, 0, n * sizeof(*result));
-    return result;
-  }
-
-  // Returns an aligned pointer in the C heap with room for size bytes.
-  // Alignment must be >= 16 and a power of two.
-  static void* AlignedAllocate(intptr_t size, intptr_t alignment);
-
-  // Frees a pointer returned from AlignedAllocate.
-  static void AlignedFree(void* ptr);
-
   // Returns the activation frame alignment constraint or one if
   // the platform doesn't care. Guaranteed to be a power of two.
   static intptr_t ActivationFrameAlignment();