[llvm] [TableGen][DecoderEmitter] Report all decoding conflicts (PR #157847)

[Sergei Barannikov via llvm-commits]

================
@@ -2585,7 +2598,10 @@ template <typename T> constexpr uint32_t InsnBitWidth = 0;
       //    across all decoder tables.
       //  - predicates are shared across all decoder tables.
       TableInfo.Table.clear();
-      TableBuilder.buildTable(FC, BitWidth);
+      HasConflict |= TableBuilder.buildTable(FC, BitWidth);
+      // Skip emitting table entries if a conflict has been detected.
+      if (HasConflict)
+        continue;
----------------
s-barannikov wrote:

```suggestion
      if (FC.HasConflict)
        continue;
      TableBuilder.buildTable(FC, BitWidth);
```

https://github.com/llvm/llvm-project/pull/157847