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

[Rahul Joshi via llvm-commits]

================
@@ -10,16 +10,14 @@ class I : Instruction {
 
 // Check pretty printing of decoding conflicts.
 
-// CHECK:      {{^}}Decoding Conflict:
-// CHECK-NEXT: {{^}}                    ........
-// CHECK-NEXT: {{^}}            ..............11
-// CHECK-NEXT: {{^}}            .......0......11
-// CHECK-NEXT: {{^}}            _______0______11  I16_0
-// CHECK-NEXT: {{^}}            _______0______11  I16_1
-// CHECK-NEXT: {{^}}    _______0_______0______11  I24_0
+// CHECK:      Decoding Conflict:
+// CHECK-NEXT:             ................
----------------
jurahul wrote:

This is the output I get currently:

```
Decoding Conflict:
            ................
            ..............11
            .......0......11
            _______0______11  I16_0
            _______0______11  I16_1
    _______0_______0______11  I24_0
```

The 8 dots were due to the I8_0/1 which I had deleted (I though they were causing some issues, but I don't see it anymore). So I've reinstated them and fixed the file, so there is no diff here anymore.

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