[llvm] [AMDGPU] Ignore unused VALU src0/1/2 fields when disassembling (PR #175182)

[Ivan Kosarev via llvm-commits]

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@@ -2559,6 +2559,9 @@
 0x00,0x00,0x00,0x7e
 # GFX10: v_nop                                   ; encoding: [0x00,0x00,0x00,0x7e]
 
+0xff,0x01,0x00,0x7e
+# GFX10: v_nop                                   ; encoding: [0x00,0x00,0x00,0x7e]
+
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kosarev wrote:

This assumes `InOperandList` is itself formed by looking at HasSrc0/1, which might not be the case.

TableGen may be checking that `Inst` agrees with `InOperandList`, but what I'm aiming at here is making sure the HasSrc0/1 values are still correct where the `!if`s are removed.

https://github.com/llvm/llvm-project/pull/175182