[clang] [llvm] [CMake] Detect properly new linker introduced in Xcode 15 (PR #77806)

[Louis Dionne via cfe-commits]

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@@ -211,10 +211,10 @@ if (NOT DEFINED LLVM_LINKER_DETECTED AND NOT WIN32)
     )
 
   if(APPLE)
-    if("${stderr}" MATCHES "PROJECT:ld64")
+    if("${stderr}" MATCHES "PROGRAM:ld")
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ldionne wrote:

I'm not certain I understand -- isn't this patch missing something so that it keeps working on pre Xcode 15 toolchains? Libc++ supports Xcode 15 only, but the rest of LLVM probably supports older versions as well?

https://github.com/llvm/llvm-project/pull/77806