[llvm] [AMDGPU][GFX12] Add tests for {image/flat}_atomic_pk (PR #78683)

[Jay Foad via llvm-commits]

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@@ -1018,6 +1018,60 @@
 # GFX12: image_atomic_max_flt v0, v0, s[0:7] dmask:0x1 dim:SQ_RSRC_IMG_1D th:TH_ATOMIC_NT ; encoding: [0x00,0x40,0x61,0xd0,0x00,0x00,0x20,0x00,0x00,0x00,0x00,0x00]
 0x00,0x40,0x61,0xd0,0x00,0x00,0x20,0x00,0x00,0x00,0x00,0x00
 
+# GFX12: image_atomic_pk_add_f16 v0, v0, s[0:7] dmask:0x1 dim:SQ_RSRC_IMG_1D ; encoding: [0x00,0x80,0x61,0xd0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]
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jayfoad wrote:

Same.

https://github.com/llvm/llvm-project/pull/78683