Use where instead of filter for for loops

With swiftlang/swift-syntax#1958, `node.filter` will return a new `SyntaxCollection` that has the filtered elements removed (instead of the array it’s currently returning). Since that node has elements removed, it will have a new parent and thus all the nodes inside of it have new IDs. Use `where` after `for` to get the elements with the same IDs and just don’t iterate the elements that don’t satisfy the condition. This is also more performant because it doesn’t create an intermediate array.

Author: ahoppen

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -744,7 +744,7 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
 
     // An if-configuration clause around a switch-case encloses the case's node, so an
     // if-configuration clause requires a break here in order to be allowed on a new line.
-    for ifConfigDecl in node.cases.filter({ $0.is(IfConfigDeclSyntax.self) }) {
+    for ifConfigDecl in node.cases where ifConfigDecl.is(IfConfigDeclSyntax.self) {
       if config.indentSwitchCaseLabels {
         before(ifConfigDecl.firstToken(viewMode: .sourceAccurate), tokens: .break(.open))
         after(ifConfigDecl.lastToken(viewMode: .sourceAccurate), tokens: .break(.close, size: 0))