[clang] Remove Diag parameter from Expr::EvaluateKnownConstInt

If it's truly a known const int, it won't emit any diagnostics anyway.
And if it did, we wouldn't notice because the parameter was never set to
anything.

Author: tbaederr

clang/include/clang/AST/Expr.h

@@ -715,9 +715,7 @@ class Expr : public ValueStmt {
   /// EvaluateKnownConstInt - Call EvaluateAsRValue and return the folded
   /// integer. This must be called on an expression that constant folds to an
   /// integer.
-  llvm::APSInt EvaluateKnownConstInt(
-      const ASTContext &Ctx,
-      SmallVectorImpl<PartialDiagnosticAt> *Diag = nullptr) const;
+  llvm::APSInt EvaluateKnownConstInt(const ASTContext &Ctx) const;
 
   llvm::APSInt EvaluateKnownConstIntCheckOverflow(
       const ASTContext &Ctx,

clang/lib/AST/ExprConstant.cpp

@@ -17863,14 +17863,12 @@ bool Expr::isEvaluatable(const ASTContext &Ctx, SideEffectsKind SEK) const {
          !hasUnacceptableSideEffect(Result, SEK);
 }
 
-APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx,
-                    SmallVectorImpl<PartialDiagnosticAt> *Diag) const {
+APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx) const {
   assert(!isValueDependent() &&
          "Expression evaluator can't be called on a dependent expression.");
 
   ExprTimeTraceScope TimeScope(this, Ctx, "EvaluateKnownConstInt");
   EvalResult EVResult;
-  EVResult.Diag = Diag;
   EvalInfo Info(Ctx, EVResult, EvaluationMode::IgnoreSideEffects);
   Info.InConstantContext = true;