[clang] Revert "[clang] Silence GCC warnings about control reaching end of non void function" (PR #108646)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Florian Mayer (fmayer)

<details>
<summary>Changes</summary>

This reverts commit 90a2e0bb423629b7e70f4b91adb44851199dd5ea.

Reverting parent CL


---
Full diff: https://github.com/llvm/llvm-project/pull/108646.diff


2 Files Affected:

- (modified) clang/include/clang/Basic/DiagnosticIDs.h (-2) 
- (modified) clang/lib/Sema/SemaOverload.cpp (-1) 


``````````diff
diff --git a/clang/include/clang/Basic/DiagnosticIDs.h b/clang/include/clang/Basic/DiagnosticIDs.h
index daad66f499538f..2402996ece5c94 100644
--- a/clang/include/clang/Basic/DiagnosticIDs.h
+++ b/clang/include/clang/Basic/DiagnosticIDs.h
@@ -18,7 +18,6 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Support/ErrorHandling.h"
 #include <optional>
 #include <vector>
 
@@ -311,7 +310,6 @@ class DiagnosticIDs : public RefCountedBase<DiagnosticIDs> {
         return {diag::Severity::Fatal, std::string(Message), CLASS_ERROR,
                 /*ShowInSystemHeader*/ true};
       }
-      llvm_unreachable("Fully covered switch above!");
     }());
   }
 
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 382630ed674107..d3e009a658f0e8 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -7331,7 +7331,6 @@ static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const NamedDecl *ND,
     case DiagnoseIfAttr::DS_error:
       return diag::Severity::Error;
     }
-    llvm_unreachable("Fully covered switch above!");
   };
 
   for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))

``````````

</details>


https://github.com/llvm/llvm-project/pull/108646