[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:

As a follow-up to this: `RISCVTuneProcessorModel<"generic", ...>` is revert back to NoSchedModel, because any "generic" -- either `-mcpu=generic` or `-mtune=generic` -- will boil down to generic-rv32/rv64 now.

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