[llvm] [RISCV] Adopt SpacemitX60's scheduling model for `-mtune=generic` (PR #167008)

[Min-Yih Hsu via llvm-commits]

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@@ -102,7 +102,12 @@ def GENERIC_RV64 : RISCVProcessorModel<"generic-rv64",
                    GenericTuneInfo;
 // Support generic for compatibility with other targets. The triple will be used
 // to change to the appropriate rv32/rv64 version.
-def GENERIC : RISCVTuneProcessorModel<"generic", NoSchedModel>, GenericTuneInfo;
+// `generic` is expected to target in-order application processors designed for
+// general-purpose computing.
+def GENERIC : RISCVTuneProcessorModel<"generic", SpacemitX60Model>,
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mshockwave wrote:

It does, but it will not remap `-mtune=generic`.
So after this patch, `-mtune=generic` effectively becomes `-mtune=spacemit-x60` while `-mcpu=generic/generic-rv32/generic-rv64` stay the same.

Now, if we want to make `-mtune=generic` and `-mcpu=generic` having the same behavior, then we need to update nearly all the test cases, hence the question I raised in the PR description.

https://github.com/llvm/llvm-project/pull/167008