compiletest: Remove the `-test` suffix from normalize directives
This suffix was an artifact of using the same condition-checking engine as the `ignore-*` and `only-*` directives, but in practice we have only 2 tests that legitimately use a condition, and both of them only care about 32-bit vs 64-bit.
This PR detaches `normalize-*` directives from the condition checker, and replaces it with a much simpler system of four explicit `NormalizeKind` values. It then takes advantage of that simplicity to get rid of the `-test` suffix.
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Addresses one of the points of #126372.
The new name-checking code is a bit quaint, but I think it's a definite improvement over the status quo.
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The corresponding dev-guide update is https://github.com/rust-lang/rustc-dev-guide/pull/2172.
r? jieyouxu
bc3e8917e3