[clang] [NFC][clang][AST] Add compile-time dispatch for random access iterators in append() (PR #162000)

[Samarth Narang via cfe-commits]

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@@ -180,9 +180,21 @@ class ASTVector {
   size_t capacity() const { return this->capacity_ptr() - Begin; }
 
   /// append - Add the specified range to the end of the SmallVector.
-  template<typename in_iter>
+  template <typename in_iter>
   void append(const ASTContext &C, in_iter in_start, in_iter in_end) {
-    size_type NumInputs = std::distance(in_start, in_end);
+    using size_type =
+        typename std::remove_reference_t<decltype(*this)>::size_type;
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snarang181 wrote:

Thanks for catching that, resolved.

https://github.com/llvm/llvm-project/pull/162000