[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[];
+  const int *defaultparam1(const int &def1 [[clang::lifetimebound]] = 0); // #def1
+  const int &defaultparam_array([[clang::lifetimebound]] const int *p = IntArray{1, 2, 3}); // #def2
+  struct A {
+    A(const char*, const int& def3 [[clang::lifetimebound]] = 0); // #def3
+  };
+  const int &defaultparam2(const int &def4 [[clang::lifetimebound]] = 0); // #def4
+  const int &defaultparam3(const int &def5 [[clang::lifetimebound]] = defaultparam2()); // #def5
+  std::string_view defaultparam4(std::string_view s [[clang::lifetimebound]] = std::string()); // #def6
+
+  const int*test_default_args() {
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higher-performance wrote:

Done.

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