[clang] Make [[clang::lifetimebound]] work for expressions coming from default arguments (PR #112047)

[via cfe-commits]

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@@ -107,6 +107,39 @@ namespace std {
 using std::operator""s;
 using std::operator""sv;
 
+namespace default_args {
+  using IntArray = int[];
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higher-performance wrote:

It's necessary for the usage syntax. I don't think `int[]{1, 2, 3}` would be legal.

https://github.com/llvm/llvm-project/pull/112047