[llvm] [AMDGPU] Relax long branches in the assembler on gfx1251 (PR #228363)

[Matt Arsenault via llvm-commits]

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@@ -1648,6 +1648,30 @@ defm S_CBRANCH_CDBGUSER : SOPP_With_Relaxation <
 } // End isBranch = 1
 } // End isTerminator = 1
 
+// Long branches that MC branch relaxation can create on subtargets with
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arsenm wrote:

I'm not sure why you need these pseudos instead of directly using the branches. The names look too much like plausibly real instructions 

https://github.com/llvm/llvm-project/pull/228363