Force the correction of delayed typos in casts in non-C++ code.

Fixes PR21656, which is fallout from r222551 caused by an untested/missed
code path.

llvm-svn: 222694

clang/lib/Sema/SemaExpr.cpp

@@ -5299,6 +5299,12 @@ Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
   if (getLangOpts().CPlusPlus) {
     // Check that there are no default arguments (C++ only).
     CheckExtraCXXDefaultArguments(D);
+  } else {
+    // Make sure any TypoExprs have been dealt with.
+    ExprResult Res = CorrectDelayedTyposInExpr(CastExpr);
+    if (!Res.isUsable())
+      return ExprError();
+    CastExpr = Res.get();
   }
 
   checkUnusedDeclAttributes(D);

clang/test/Sema/typo-correction.c

@@ -4,3 +4,8 @@
 // than in C++ and may exhibit different behavior as a result.
 
 __typeof__(struct F*) var[invalid];  // expected-error-re {{use of undeclared identifier 'invalid'{{$}}}}
+
+void PR21656() {
+  float x;
+  x = (float)arst;  // expected-error-re {{use of undeclared identifier 'arst'{{$}}}}
+}