[Clang] skip consumed analysis for consteval conditions in control-flow terminators (#117403)

Fixes #117385

---

These changes extend the work done in #116513. The changes add
additional handling to ensure correct behavior by skipping further
checks when a **CFG** contains a `consteval` condition, where no
_explicit expression_ is present, which is required to proceed with
consumed analyses.

Author: a-tarasyuk

clang/docs/ReleaseNotes.rst

@@ -725,6 +725,7 @@ Bug Fixes to C++ Support
 - Clang now uses valid deduced type locations when diagnosing functions with trailing return type
   missing placeholder return type. (#GH78694)
 - Fixed a bug where bounds of partially expanded pack indexing expressions were checked too early. (#GH116105)
+- Fixed an assertion failure caused by using ``consteval`` in condition in consumed analyses. (#GH117385)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Analysis/Consumed.cpp

@@ -1229,6 +1229,9 @@ bool ConsumedAnalyzer::splitState(const CFGBlock *CurrBlock,
 
   if (const auto *IfNode =
           dyn_cast_or_null<IfStmt>(CurrBlock->getTerminator().getStmt())) {
+    if (IfNode->isConsteval())
+      return false;
+
     const Expr *Cond = IfNode->getCond();
 
     PInfo = Visitor.getInfo(Cond);

clang/test/SemaCXX/constexpr-return-non-void-cxx2b.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++23 -fsyntax-only -Wimplicit-fallthrough -verify %s
+// RUN: %clang_cc1 -std=c++23 -fsyntax-only -Wimplicit-fallthrough -Wconsumed -verify %s
 
 constexpr int f() { } // expected-warning {{non-void function does not return a value}}
 static_assert(__is_same(decltype([] constexpr -> int { }( )), int)); // expected-warning {{non-void lambda does not return a value}}
@@ -34,3 +34,10 @@ constinit bool l = j(); // expected-error {{variable does not have a constant in
                         // expected-note {{in call to 'j()'}}
 
 }
+
+namespace GH117385 {
+void f() {
+  if consteval {
+  }
+}
+}