[clang] [Clang] Link libgcc_s.1.dylib when building for macOS 10.5 and older (PR #141401)

[Steven Wu via cfe-commits]

================
@@ -1645,14 +1645,14 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
     CmdArgs.push_back("-lSystem");
 
   // Select the dynamic runtime library and the target specific static library.
-  if (isTargetIOSBased()) {
-    // If we are compiling as iOS / simulator, don't attempt to link libgcc_s.1,
-    // it never went into the SDK.
-    // Linking against libgcc_s.1 isn't needed for iOS 5.0+
-    if (isIPhoneOSVersionLT(5, 0) && !isTargetIOSSimulator() &&
-        getTriple().getArch() != llvm::Triple::aarch64)
-      CmdArgs.push_back("-lgcc_s.1");
-  }
+  // If we are compiling as iOS / simulator, don't attempt to link libgcc_s.1,
----------------
cachemeifyoucan wrote:

I suggest consolidating those comments into one for explaining when libgcc is used, basically:
* below macOS 10.6
* below iOS 5.0 but device only (not simulator)
* not on arm64 since libgcc is obsoleted before its existence.

https://github.com/llvm/llvm-project/pull/141401