[clang] Suppress noreturn warning if last statement in a function is a throw (PR #145166)

[Yanzuo Liu via cfe-commits]

================
@@ -681,6 +705,30 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
       if (CD.diag_FallThrough_HasNoReturn)
         S.Diag(RBrace, CD.diag_FallThrough_HasNoReturn) << CD.FunKind;
     } else if (!ReturnsVoid && CD.diag_FallThrough_ReturnsNonVoid) {
+      // If the final statement is a call to an always-throwing function,
+      // don't warn about the fall-through.
+      if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
+        if (const auto *CS = dyn_cast<CompoundStmt>(Body)) {
+          if (!CS->body_empty()) {
----------------
zwuis wrote:

```cpp
if (const auto *CS = dyn_cast<CompoundStmt>(Body);
    CS && !CS->body_empty()) {
```
To avoid deep indentation.

https://github.com/llvm/llvm-project/pull/145166