[AST][RecoveryExpr] Don't perform early typo correction in C.

[hokein]

Summary

The dependent mechanism for C error-recovery is mostly finished,
this is the only place we have missed.

clang/lib/Sema/SemaExpr.cpp

 }
 
 /// ActOnConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null
 /// in the case of a the GNU conditional expr extension.
 ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc,
                                     SourceLocation ColonLoc,
                                     Expr *CondExpr, Expr *LHSExpr,
                                     Expr *RHSExpr) {
-  if (!getLangOpts().CPlusPlus) {
+  if (!Context.isDependenceAllowed()) {
     // C cannot handle TypoExpr nodes in the condition because it
     // doesn't handle dependent types properly, so make sure any TypoExprs have
     // been dealt with before checking the operands.
     ExprResult CondResult = CorrectDelayedTyposInExpr(CondExpr);
     ExprResult LHSResult = CorrectDelayedTyposInExpr(LHSExpr);
     ExprResult RHSResult = CorrectDelayedTyposInExpr(RHSExpr);
 
     if (!CondResult.isUsable())

clang/test/AST/ast-dump-recovery.c

 // CHECK-NEXT:  `-ParenExpr {{.*}}
 // CHECK-NEXT:    `-BinaryOperator {{.*}} '+'
 // CHECK-NEXT:      |-ImplicitCastExpr
 // CHECK-NEXT:      | `-DeclRefExpr {{.*}} 'a'
 // CHECK-NEXT:      `-IntegerLiteral {{.*}} 'int'
 int unary_address = &(a + 1);
 
 // CHECK:       VarDecl {{.*}} ternary 'int' cinit
-// CHECK-NEXT:  `-RecoveryExpr {{.*}}
+// CHECK-NEXT:  `-ConditionalOperator {{.*}}
 // CHECK-NEXT:    |-DeclRefExpr {{.*}} 'a'
-// CHECK-NEXT:    |-TypoExpr {{.*}}
+// CHECK-NEXT:    |-RecoveryExpr {{.*}}
 // CHECK-NEXT:    `-DeclRefExpr {{.*}} 'a'
-// FIXME: The TypoExpr should never be print, and should be downgraded to
-// RecoveryExpr -- typo correction is performed too early in C-only codepath,
-// which makes no correction when clang finishes the full expr (Sema::Sema::ActOnFinishFullExpr).
-// this will be fixed when we support dependent mechanism and delayed typo correction for C.
 int ternary = a ? undef : a;
 
 void test1() {
   // CHECK:     `-RecoveryExpr {{.*}} contains-errors
   // CHECK-NEXT:  `-DeclRefExpr {{.*}} 'a' 'const int'
   static int foo = a++; // verify no crash on local static var decl.
 }