[llvm] [RISCV][GISel] Move G_BRJT expansion to legalization (PR #73711)

[Matt Arsenault via llvm-commits]

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@@ -317,6 +318,61 @@ bool RISCVLegalizerInfo::legalizeShlAshrLshr(
   return true;
 }
 
+bool RISCVLegalizerInfo::legalizeBRJT(MachineInstr &MI,
+                                      MachineIRBuilder &MIRBuilder) const {
+  MachineRegisterInfo &MRI = *MIRBuilder.getMRI();
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arsenm wrote:

Can all of this except the Custom32 case go into the generic legalizer?

https://github.com/llvm/llvm-project/pull/73711