[AST] Rename TypeCheckedAtOnce to TypeCheckedWithSignature

To clarify the meaning

Author: rintaro

include/swift/AST/Expr.h

@@ -3769,7 +3769,7 @@ class ClosureExpr : public AbstractClosureExpr {
 
     /// The body was typechecked with the enclosing closure.
     /// i.e. single expression closure or function builder closure.
-    TypeCheckedAtOnce,
+    TypeCheckedWithSignature,
 
     /// The body was type checked separately from the enclosing closure.
     SeparatelyTypeChecked,

lib/Sema/CSClosure.cpp

@@ -345,7 +345,7 @@ SolutionApplicationToFunctionResult ConstraintSystem::applySolution(
     ClosureConstraintApplication application(
         solution, closure, closureFnType->getResult(), rewriteTarget);
     application.visit(fn.getBody());
-    closure->setBodyState(ClosureExpr::BodyState::TypeCheckedAtOnce);
+    closure->setBodyState(ClosureExpr::BodyState::TypeCheckedWithSignature);
 
     return SolutionApplicationToFunctionResult::Success;
   }

lib/Sema/TypeCheckConstraints.cpp

@@ -2320,7 +2320,7 @@ bool TypeChecker::typeCheckForEachBinding(DeclContext *dc, ForEachStmt *stmt) {
     // Invalidate the pattern and the var decl.
     stmt->getPattern()->setType(ErrorType::get(Context));
     stmt->getPattern()->forEachVariable([&](VarDecl *var) {
-      if (var->hasInterfaceType() && !var->getType()->hasError())
+      if (var->hasInterfaceType() && !var->isInvalid())
         return;
       var->setInvalid();
     });
@@ -2403,7 +2403,7 @@ bool TypeChecker::typeCheckConditionForStatement(LabeledConditionalStmt *stmt,
       elt.getPattern()->forEachVariable([&](VarDecl *var) {
         // Don't change the type of a variable that we've been able to
         // compute a type for.
-        if (var->hasInterfaceType() && !var->getType()->hasError())
+        if (var->hasInterfaceType() && !var->isInvalid())
           return;
         var->setInvalid();
       });