[clang] [BPF] make __BPF_FEATURE_MAY_GOTO available for cpuv1 (PR #108071)

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eddyz87 wrote:

@yonghong-song, @4ast,

As a cleanup, Yonghong suggested moving `__BPF_FEATURE_MAY_GOTO` macro so that it is available for CPUv1.
(Although, I think it's better to move both `__BPF_FEATURE_MAY_GOTO` and `__BPF_FEATURE_ADDR_SPACE_CAST` down to CPUv4, as this would be more consistent with kernel features support).

Wdyt?

https://github.com/llvm/llvm-project/pull/108071