[ASTGen] Adjustments for the deprecation of CanImportExpr and CanImportVersionInfo

Author: ahoppen

lib/ASTGen/Sources/ASTGen/Exprs.swift

@@ -51,7 +51,7 @@ func isExprMigrated(_ node: ExprSyntax) -> Bool {
       break
 
     // Known unimplemented kinds.
-    case .asExpr, .canImportExpr, .canImportVersionInfo,
+    case .asExpr, 
       .doExpr, .editorPlaceholderExpr, .floatLiteralExpr, .forceUnwrapExpr,
       .inOutExpr, .infixOperatorExpr, .isExpr, .keyPathExpr,
       .macroExpansionExpr, .optionalChainingExpr,
@@ -97,10 +97,6 @@ extension ASTGenVisitor {
       return self.generate(booleanLiteralExpr: node).asExpr
     case .borrowExpr(let node):
       return self.generate(borrowExpr: node).asExpr
-    case .canImportExpr:
-      break
-    case .canImportVersionInfo:
-      break
     case .closureExpr(let node):
       return self.generate(closureExpr: node).asExpr
     case .consumeExpr(let node):
@@ -188,6 +184,8 @@ extension ASTGenVisitor {
       preconditionFailure("should be handled in generate(sequenceExpr:)")
     case .unresolvedTernaryExpr:
       preconditionFailure("should be handled in generate(sequenceExpr:)")
+    case ._canImportExpr, ._canImportVersionInfo:
+      preconditionFailure("should not be generated by the parser anymore")
 #if RESILIENT_SWIFT_SYNTAX
     @unknown default:
       fatalError()