Add missing keywords in swift (#4153)

Author: Arun

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SwiftClientCodegen.java

@@ -136,14 +136,16 @@ public SwiftClientCodegen() {
                         "ErrorResponse",
 
                         // swift keywords
+                        // https://docs.swift.org/swift-book/ReferenceManual/LexicalStructure.html Section: Keywords and Punctuation
                         "Int", "Int32", "Int64", "Int64", "Float", "Double", "Bool", "Void", "String", "Character", "AnyObject",
                         "class", "Class", "break", "as", "associativity", "deinit", "case", "dynamicType", "convenience", "enum", "continue",
                         "false", "dynamic", "extension", "default", "is", "didSet", "func", "do", "nil", "final", "import", "else",
                         "self", "get", "init", "fallthrough", "Self", "infix", "internal", "for", "super", "inout", "let", "if",
                         "true", "lazy", "operator", "in", "COLUMN", "left", "private", "return", "FILE", "mutating", "protocol",
                         "switch", "FUNCTION", "none", "public", "where", "LINE", "nonmutating", "static", "while", "optional",
                         "struct", "override", "subscript", "postfix", "typealias", "precedence", "var", "prefix", "Protocol",
-                        "required", "right", "set", "Type", "unowned", "weak", "Data")
+                        "required", "right", "set", "Type", "unowned", "weak", "Data","fileprivate", "open", "rethrows", "defer",
+                        "guard", "repeat", "Any", "catch", "throw", "throws", "try", "indirect", "willSet")
         );
 
         typeMapping = new HashMap<String, String>();