Xcode: Evaluate Swift compile definitions separately

Xcode has a separate setting for Swift compile definitions, so we can
compute a dedicated value for it.  Therefore we can:

* Support the COMPILE_LANGUAGE generator expression for Swift-specific
  filters.

* Avoid passing the `=value` part of definitions, which Swift does
  not support.

This revises commit 5cb625eb2f (Xcode: Pass compile definitions to
Swift, 2022-06-19, v3.25.0-rc1~493^2) and reverts commit 12c6fec6b4
(Xcode: Drop CMAKE_INTDIR= definition in Swift targets, 2022-09-30,
v3.25.0-rc1~60^2~2), as the latter is no longer needed.

Fixes: #24086

1 files changed, 20 insertions, 0 deletions

diff --git a/Tests/SwiftMix/SwiftMain.swift b/Tests/SwiftMix/SwiftMain.swift
index d9c8cd7..238059d 100644
--- a/Tests/SwiftMix/SwiftMain.swift
+++ b/Tests/SwiftMix/SwiftMain.swift
@@ -3,6 +3,26 @@ import Foundation
 @objc class SwiftMainClass : NSObject {
   @objc class func SwiftMain() -> Int32 {
     dump("Hello World!");
+#if FOO
+    dump("FOO defined");
+#else
+    fatalError("FOO not defined");
+#endif
+#if BAR
+    dump("BAR defined");
+#else
+    fatalError("BAR not defined");
+#endif
+#if CCOND
+    fatalError("CCOND defined");
+#else
+    dump("CCOND not defined");
+#endif
+#if SWIFTCOND
+    dump("SWIFTCOND defined");
+#else
+    fatalError("SWIFTCOND not defined");
+#endif
     return 0;
   }
 }