[llvm] [CodeGen][GC] Skip function without GC in `GCLoweringPass` (PR #84421)

[Matt Arsenault via llvm-commits]

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@@ -31,6 +32,8 @@ entry:
 	%B.1 = load ptr, ptr %B
 	%A.1 = load ptr, ptr %A
 	call void @llvm.gcwrite(ptr %A.1, ptr %B.upgrd.1, ptr %B.1)
+	; CHECK-NOT: call void @llvm.gcwrite(ptr %A.1, ptr %B.upgrd.1, ptr %B.1)
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arsenm wrote:

-NOT checks are perilous and should be as lax as possible. Better would be -NEXT checks to show it's not present 

https://github.com/llvm/llvm-project/pull/84421