[lld] [lld] Add target support for SystemZ (s390x) (PR #75643)

[Ulrich Weigand via llvm-commits]

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@@ -0,0 +1,73 @@
+// REQUIRES: systemz
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uweigand wrote:

Done.   This actually uncovered a bug - it was possible for `.got` to be removed completely in a file that uses `.plt` - but the PLT header refers to `_GLOBAL_OFFSET_TABLE_` which points to the start of `.got` on SystemZ ...   Fixed by enforcing the presence of `.got` in `SystemZ::addPltHeaderSymbols`.

https://github.com/llvm/llvm-project/pull/75643