[ExprConst] Handle floating- and char literals in FastEvaluateAsRValue

Author: tbaederr

clang/lib/AST/ExprConstant.cpp

@@ -16473,7 +16473,7 @@ static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
                                  const ASTContext &Ctx, bool &IsConst) {
   // Fast-path evaluations of integer literals, since we sometimes see files
   // containing vast quantities of these.
-  if (const IntegerLiteral *L = dyn_cast<IntegerLiteral>(Exp)) {
+  if (const auto *L = dyn_cast<IntegerLiteral>(Exp)) {
     Result.Val = APValue(APSInt(L->getValue(),
                                 L->getType()->isUnsignedIntegerType()));
     IsConst = true;
@@ -16486,6 +16486,18 @@ static bool FastEvaluateAsRValue(const Expr *Exp, Expr::EvalResult &Result,
     return true;
   }
 
+  if (const auto *FL = dyn_cast<FloatingLiteral>(Exp)) {
+    Result.Val = APValue(FL->getValue());
+    IsConst = true;
+    return true;
+  }
+
+  if (const auto *L = dyn_cast<CharacterLiteral>(Exp)) {
+    Result.Val = APValue(Ctx.MakeIntValue(L->getValue(), L->getType()));
+    IsConst = true;
+    return true;
+  }
+
   if (const auto *CE = dyn_cast<ConstantExpr>(Exp)) {
     if (CE->hasAPValueResult()) {
       APValue APV = CE->getAPValueResult();