[Clang][P1061] Add stuctured binding packs (#121417)

This is an implementation of P1061 Structure Bindings Introduce a Pack
without the ability to use packs outside of templates. There is a couple
of ways the AST could have been sliced so let me know what you think.
The only part of this change that I am unsure of is the
serialization/deserialization stuff. I followed the implementation of
other Exprs, but I do not really know how it is tested. Thank you for
your time considering this.

---------

Co-authored-by: Yanzuo Liu <zwuis@outlook.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaExceptionSpec.cpp b/clang/lib/Sema/SemaExceptionSpec.cpp
index 470d0d7..7b08a06 100644
--- a/clang/lib/Sema/SemaExceptionSpec.cpp
+++ b/clang/lib/Sema/SemaExceptionSpec.cpp
@@ -1068,7 +1068,7 @@ static CanThrowResult canVarDeclThrow(Sema &Self, const VarDecl *VD) {
 
   // If this is a decomposition declaration, bindings might throw.
   if (auto *DD = dyn_cast<DecompositionDecl>(VD))
-    for (auto *B : DD->bindings())
+    for (auto *B : DD->flat_bindings())
       if (auto *HD = B->getHoldingVar())
         CT = mergeCanThrow(CT, canVarDeclThrow(Self, HD));
 
@@ -1286,6 +1286,7 @@ CanThrowResult Sema::canThrow(const Stmt *S) {
   case Expr::ConvertVectorExprClass:
   case Expr::VAArgExprClass:
   case Expr::CXXParenListInitExprClass:
+  case Expr::ResolvedUnexpandedPackExprClass:
     return canSubStmtsThrow(*this, S);
 
   case Expr::CompoundLiteralExprClass: