Revert "Change compiler checks"

This reverts commit 310e8ea.

Author: FranzBusch

Sources/HTTPTypesFoundation/URLSession+HTTPTypes.swift

@@ -45,7 +45,7 @@ private enum HTTPTypeConversionError: Error {
 
 #endif
 
-#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || compiler(>=6)
+#if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || compiler(>=6) || (compiler(>=6) && os(visionOS))
 
 @available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
 extension URLSession {
@@ -129,7 +129,7 @@ extension URLSession {
         return (location, response)
     }
 
-    #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || compiler(>=6)
+    #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || (compiler(>=6) && os(visionOS))
     /// Returns a byte stream that conforms to AsyncSequence protocol.
     ///
     /// - Parameter request: The `HTTPRequest` for which to load data.