[lld] [LLD, MachO] Default objc_relative_method_lists on MacOS11+/iOS14+ (PR #101360)

[Peter Rong via llvm-commits]

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@@ -2,15 +2,15 @@
 # UNSUPPORTED: target=arm{{.*}}-unknown-linux-gnueabihf
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DataCorrupted wrote:

1. MacOS 10 => defaults to not relative
2. MacOS 11 => defaults to relative
3. MacOS 10 + -objc_relative_method_lists => relative
4. MacOS 12 + -no_objc_relative_method_lists=> not relative

2. Should be covered by removing `-objc_relative_method_lists` in the tests 
4. Should be covered by unchanged `-no_objc_relative_method_lists` on [Line 17](https://github.com/DataCorrupted/llvm-project/blob/HEAD/lld/test/MachO/objc-relative-method-lists-simple.s#L17C1-L17C135) (on MacOS 11 tho)

I need to modify lit config to test 1 and 3 (our lit config defaults to MacOS 11 now). I tried yesterday but with no luck. Let me try it again.

https://github.com/llvm/llvm-project/pull/101360