[llvm] [AMDGPU] Mark S_NOP as having side effects (PR #65745)

[Jay Foad via llvm-commits]

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@@ -72,8 +72,7 @@
   ; GFX908-NEXT:    ; implicit-def: $vgpr59
   ; GFX908-NEXT:    ; implicit-def: $vgpr60
   ; GFX908-NEXT:    ; implicit-def: $vgpr61
-  ; GFX908-NEXT:    s_nop 0
-  ; GFX908-NEXT:    s_nop 0
+  ; GFX908-NEXT:    s_nop 1
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jayfoad wrote:

GCNHazardRecognizer wants to delay for 2 cycles here. If there was already an S_NOP 0 here it would add another one, instead of modifying it to be an S_NOP 1.

https://github.com/llvm/llvm-project/pull/65745