[llvm] [GlobalISel] Add and use a m_GAddLike pattern matcher. NFC (PR #125435)

[Matt Arsenault via llvm-commits]

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@@ -337,6 +343,21 @@ template <> struct bind_helper<MachineInstr *> {
   }
 };
 
+template <> struct bind_helper<const MachineInstr *> {
+  static bool bind(const MachineRegisterInfo &MRI, const MachineInstr *&MI,
+                   Register Reg) {
+    MI = MRI.getVRegDef(Reg);
+    if (MI)
+      return true;
+    return false;
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arsenm wrote:

Fold to return of bool expression 

https://github.com/llvm/llvm-project/pull/125435