[clang] [HLSL] error on out of bounds vector accesses (PR #128952)

[Chris B via cfe-commits]

================
@@ -10635,6 +10635,12 @@ def err_block_on_vm : Error<
 def err_sizeless_nonlocal : Error<
   "non-local variable with sizeless type %0">;
 
+def err_vector_index_out_of_range : Error<
+  "vector element index %0 is out of bounds">;
+def warn_vector_index_out_of_range : Warning<
+  "vector element index %0 is out of bounds">,
----------------
llvm-beanz wrote:

Since these share the same text we can just have them refer to each other.
```suggestion
  "vector element index %0 is out of bounds">;
def warn_vector_index_out_of_range : Warning<
  err_vector_index_out_of_range.Summary>,
```

https://github.com/llvm/llvm-project/pull/128952