[llvm] [BPF] Allow libcalls behind a feature gate (PR #168442)

[Lucas Ste via llvm-commits]

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@@ -1,6 +1,6 @@
 ; RUN: not llc -mtriple=bpf < %s 2> %t1
 ; RUN: FileCheck %s < %t1
-; CHECK: only small returns
+; CHECK: aggregate returns are not supported
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LucasSte wrote:

Fixed both tests in the squashed commit.

https://github.com/llvm/llvm-project/pull/168442