[llvm] TableGen: Replace assertion with error for unexpected pattern inputs (PR #159687)

[Sergei Barannikov via llvm-commits]

================
@@ -0,0 +1,25 @@
+// RUN: not llvm-tblgen -gen-dag-isel -I %p/../../include -o /dev/null %s 2>&1 | FileCheck %s
+
+include "llvm/Target/Target.td"
+
+def MyTargetInstrInfo : InstrInfo;
+def MyTarget : Target {
+  let InstructionSet = MyTargetInstrInfo;
+}
+
+def R0 : Register<"r0">;
+def GPR : RegisterClass<"MyTarget", [i32], 32, (add R0)>;
+
+def LOAD : Instruction {
+  let Size = 2;
+  let OutOperandList = (outs GPR:$dst);
+  let InOperandList = (ins GPR:$addr);
+  let AsmString = "movimm $dst, $addr";
+}
+
+// CHECK: [[@LINE+1]]:5: error: In CrashPat: unknown node type 'set in input pattern
----------------
s-barannikov wrote:

```suggestion
// CHECK: [[@LINE+1]]:5: error: In CrashPat: unknown node type 'set' in input pattern
```

https://github.com/llvm/llvm-project/pull/159687